PDX - STL

$121 Find Cheap Flights from Portland to St. Louis - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Portland to St. Louis departing on 9/8. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
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1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$240
Typical prices: $273-$486
Frontier
Thu 10/1Mon 10/5
PDX - STL • 1 stop
Cheapest non-stop
$297
Alaska Airlines
Wed 9/16Tue 9/22
PDX - STL • Non-stop
Top airlines
Cheapest • from $240 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
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Airline reviews
Airline reviews
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Nonstop flights
You can fly direct with Alaska Airlines and Southwest. Average duration is 3h 48m
Direct flights
Direct flights
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Direct flights
Direct flights
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Top layover airports
Cheapest • Avg $307 (round-trip)
Shortest trip • 5h 46m (one-way)
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 38% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 19% price drop
Most popular
Good to know
Good to know
+1
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Good to know
Good to know
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Flight Deals
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Expert advice
Flight Deals

Cheap Flights from Portland to St. Louis (PDX-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Portland to St. Louis that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Portland to St. Louis

Thu, Oct 1 - Mon, Oct 5
Frontier Logo
9:34 pm - 11:51 am
PDX
-
STL
12h 17m
1 stop
Frontier Logo
12:46 pm - 8:39 pm
STL
-
PDX
9h 53m
1 stop
$240Frontier
Wed, Aug 26 - Mon, Aug 31
Frontier Logo
5:56 pm - 7:13 pm
PDX
-
STL
23h 17m
1 stop
Frontier Logo
7:58 pm - 5:11 pm
STL
-
PDX
23h 13m
1 stop
$242Frontier
Tue, Sep 8 - Tue, Sep 15
Multiple Airlines Logo
5:56 pm - 7:17 pm
PDX
-
STL
23h 21m
1 stop
Multiple Airlines Logo
6:08 pm - 8:20 pm
STL
-
PDX
4h 12mnonstop
$275Multiple Airlines
Wed, Sep 16 - Mon, Sep 21
Multiple Airlines Logo
11:16 am - 5:10 pm
PDX
-
STL
3h 54mnonstop
Multiple Airlines Logo
8:10 pm - 2:27 pm
STL
-
PDX
20h 17m
1 stop
$278Multiple Airlines
Wed, Sep 16 - Tue, Sep 22
Alaska Airlines Logo
11:16 am - 5:10 pm
PDX
-
STL
3h 54mnonstop
Alaska Airlines Logo
6:08 pm - 8:20 pm
STL
-
PDX
4h 12mnonstop
$297Alaska Airlines
Wed, Aug 26 - Wed, Sep 2
Alaska Airlines Logo
11:16 am - 5:10 pm
PDX
-
STL
3h 54mnonstop
Alaska Airlines Logo
6:08 pm - 8:20 pm
STL
-
PDX
4h 12mnonstop
$297Alaska Airlines
Mon, Sep 21 - Sat, Sep 26
Southwest Logo
12:00 pm - 10:10 pm
PDX
-
STL
8h 10m
1 stop
Southwest Logo
8:30 am - 10:40 am
STL
-
PDX
4h 10mnonstop
$313Southwest
Sun, Sep 20 - Sat, Sep 26
Southwest Logo
11:45 am - 10:50 pm
PDX
-
STL
9h 05m
1 stop
Southwest Logo
8:30 am - 10:40 am
STL
-
PDX
4h 10mnonstop
$313Southwest
Wed, Sep 16 - Tue, Sep 22
American Airlines Logo
11:08 pm - 10:20 am
PDX
-
STL
9h 12m
1 stop
American Airlines Logo
8:00 am - 1:35 pm
STL
-
PDX
7h 35m
1 stop
$317American Airlines
Tue, Oct 27 - Sat, Oct 31
American Airlines Logo
1:12 pm - 11:58 pm
PDX
-
STL
8h 46m
1 stop
American Airlines Logo
12:46 pm - 7:29 pm
STL
-
PDX
8h 43m
1 stop
$317American Airlines
Booking Insights

KAYAK's insights & trends for Portland to St. Louis flights

Get data-powered insights and trends into flights from Portland to St. Louis to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Portland to St. Louis?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Portland to St. Louis departing in October.

Flight prices are below average for this route right now.

Flights to St. Louis from Portland usually cost between $318 and $457 in October.
The lowest price found in the past 5 days was $240 on Frontier (Oct 1-Oct 5).

What’s the cheapest day of the week to fly from Portland to St. Louis?

The average price of all round-trip flights from Portland to St. Louis clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from Portland to St. Louis, look for departures on Fridays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from St. Louis, Tuesday is the cheapest day to fly and Sunday is the most expensive.

What is the cheapest month to fly from Portland to St. Louis?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Portland to St. Louis, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Portland to St. Louis is November, where tickets cost $300 (return) on average. On the other hand, the most expensive months are July and March, where the average cost of round-trip tickets is $417 and $407 respectively.

Can I save money by flying with a layover from Portland to St. Louis?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at $357 on average.

How far in advance should I book a flight from Portland to St. Louis?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Portland to St. Louis, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Portland to St. Louis, you should book around 4 weeks before departure, which saves you about 38% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 18 weeks before departure.

Expert advice

Expert advice for your flight from Portland to St. Louis

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Gabriel Leigh

Gabriel Leigh

Expert on PDX

Gabriel is a writer and video creator. As senior content producer for Flightradar24 and Monocle’s transport correspondent, he keeps a close eye on aviation in particular. He has also written travel articles for the likes of The New York Times. Born in New York but raised around the world, he now lives in Sweden. He’s been to 75 countries, flying 2.3 million miles on 113 airlines and through 234 airports in the process.

Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Good to know

Low season

January

Cheapest flight

$121
Best time to beat the crowds with an average 11% drop in price.
Most popular time to fly with an average 2% increase in price.
Flight from Portland to St. Louis

When to book flights from Portland to St. Louis

Are your dates flexible? Find out the best times to travel from Portland to St. Louis based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Portland to St. Louis

  • Does the Portland Airport have any designated areas where children can play?

    Yes. One of these designated play areas is located landside in the D/E terminal, and the other is located airside, adjacent to Gate C17. These indoor playgrounds have seating surrounding them where parents can sit as they watch their kids run around and have fun, burning off energy before the flight to St. Louis.

  • Where can I park my car at the Portland International Airport (PDX)?

    The most affordable option at PDX is the Economy Lot, which has a free shuttle running between it and the terminals about every 10 minutes. If you want to be a bit closer to the airport and spend a little bit more money, you can opt for the long-term parking spots in Parking Garage P2 and P3.

  • Are there any private places for traveling mothers to nurse at STL?

    Yes. At the St. Louis Airport, mothers who need to nurse or pump can take advantage of the Lactation Suites located airside near Gates C7, E31, and A8. Each of these private rooms includes a comfortable chair for Mom, a table, a bench, a foot rest, an electrical outlet, and a sink.

  • Where can I pick up my rental car at STL?

    All rental car agencies at the St. Louis Airport are located off airport grounds. When you land at STL, proceed to the Arrivals curb where you can catch a free shuttle to the car rental agency where you have reserved a vehicle. These free shuttles stop at Exit 17 outside Terminal 1 and at Exit 12 outside Terminal 2. Some car rental agencies with free shuttle service to STL include National, Enterprise, Thrifty, Alamo, Hertz, Budget, and Avis.

  • What is the cheapest flight from Portland to St. Louis?

    In the last 5 days, the lowest price for a flight from Portland to St. Louis was $121 for a one-way ticket and $240 for a round-trip.

  • Do I need a passport to fly between Portland and St. Louis?

    No

  • Which airports will I be using when flying from Portland to St. Louis?

    Portland and St. Louis are both served by 1 main airport. You will leave Portland from Portland and will be arriving at Lambert-St Louis.

  • Which airlines offer Wi-Fi service onboard planes from Portland to St. Louis?

    Alaska Airlines, JetBlue, and American Airlines offer inflight Wi-Fi service on the Portland to St. Louis flight route.

  • Which aircraft models fly most regularly from Portland to St. Louis?

    The Boeing 737 MAX 9 is the aircraft model that flies most regularly on the Portland to St. Louis flight route.

  • Which airline alliances offer flights from Portland to St. Louis?

    Star Alliance, SkyTeam, and oneworld are the airline alliances operating flights between Portland and St. Louis, with Star Alliance being the most commonly used for this route.

  • On which days can I fly direct from Portland to St. Louis?

    There are nonstop flights from Portland to St. Louis on a daily basis.

  • Which is the best airline for flights from Portland to St. Louis, Southwest or Alaska Airlines?

    The two airlines most popular with KAYAK users for flights from Portland to St. Louis are Southwest and Alaska Airlines. With an average price for the route of $415 and an overall rating of 8.0, Southwest is the most popular choice. Alaska Airlines is also a great choice for the route, with an average price of $392 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from Portland to St. Louis?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Portland to St. Louis.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Portland to St. Louis?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Portland is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Portland to St. Louis?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Portland with another airline. Booking your flights between Portland and STL can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Portland to St. Louis?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Portland up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Portland to St. Louis

  • Looking for a cheap flight? 25% of our users found flights on this route for $229 or less one-way and $357 or less round-trip.
  • Located in the northwestern United States, the Portland International Airport (PDX) is a focus city for Alaska Airlines and Horizon Air. Serving as a hub for a few regional airlines, the St. Louis Lambert International Airport (STL) is located in the center of the midwest.
  • Delta, Frontier, American, and United are among the airlines that offer flights from PDX to STL with one stop. The layover is in cities such as Dallas, Phoenix, Denver, Seattle, Atlanta, Las Vegas, Minneapolis, Chicago, or Los Angeles. Alaska, Spirit,
  • Portland Airport has over 20 teams of therapy dogs and their experienced handlers who roam Departures to bring delight, distraction, and comfort to traveler's waiting for their flight.
  • If you are looking for something interesting to do as you wait for your flight to St. Louis, consider going to the Hollywood Theater, located on the C Concourse at PDX. At this small theater, you can watch short films created by Oregon filmmakers for free.
  • If you need a quiet place to decompress at STL, consider taking advantage of one of the two interfaith chapels at the St. Louis Airport. In these quiet spaces, you can relax, meditate, pray, or recoup. Along with prayer rugs and prayer books, these interfaith chapels offer religious services, empathetic listening, and spiritual guidance.

Prefer to fly direct from Portland to St. Louis?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Portland to Lambert-St Louis.
Find which airlines fly direct from Portland Airport to Lambert-St Louis Airport, which days they fly and book direct flights.

Direct departures

Portland to Lambert-St Louis

Monday

Alaska Airlines

Alaska Airlines

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines

Alaska Airlines

Friday

Alaska Airlines

Alaska Airlines

Saturday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Sunday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

See more direct flights

Direct returns

Lambert-St Louis to Portland

Monday

Alaska Airlines

Alaska Airlines

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines

Alaska Airlines

Friday

Alaska Airlines

Alaska Airlines

Saturday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Sunday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

See more direct flights

Reviews of the top 5 airlines serving from Portland to St. Louis

 
See real verified KAYAK customer reviews for airlines flying from Portland to St. Louis. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Portland to St. Louis? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4228 reviews
7.0Food
8.0Comfort
8.1Boarding
7.5Entertainment
8.6Crew
Airline reviews

I have roller bag with food and medication told me I couldn't bring on my 2nd flight today. 15 years flying with SW never an issue with that bag.

2.0 MediocreStuart, Mar 2026
HOU - STL
Read more Southwest reviews

I have roller bag with food and medication told me I couldn't bring on my 2nd flight today. 15 years flying with SW never an issue with that bag.

I have not flown Southwest in awhile and had a very pleasant experience. From ticketing to boarding to the flight. The flight left on time and landed ahead of schedule. It won't be so long next time!!

Everything went smoothly and we even arrived a little bit early.

Boarded on time but once we were ready for take off, the crew determined that, although every seat was taken, somehow someone was on the wrong flight. Delay, delay delay, announcements and ended up with one person checking EVERY ID against their passenger Manifest only to figure out it was a "clerical error." We departed 54 minutes late causing me to run in the St. Louis Airport to make my connection and lose the priority boarding spot I had paid for. Unnecessary delay.

Southwest's seats are the least comfortable I have ever sat in.

For my birthday trip this was my second time ever flying, this trip was the best.

Crew was great flight was great baggage claim was a failure. It took over 1 hour for bags to arrive. Poor communication poor effort when I spoke to the supervisor about the delay

Everything was great except the food. The pretzels are really crappy.

I had a front row middle. I am not a big person and I barely fit in between that seat! No place to put my arms, even though the guys on each side were not taking over the arm rests. It felt like a frontier flight (if that tells you everything )

Overall is was a pretty good flight. However we were 15 mins late taking off and no one told us anything. We were all in our seats just sitting there for 15mins and all the sudden the pilot stayed we are leaving now. I think they should have at least said something after our take off time passed. Everyone was wondering what was going on. I will say the pilot did increase the speed of the plane so we arrived in time. So we weren't late.

When I checked in with full service, requesting a wheelchair, as I had asked for ahead of time, the customer service agent said “wait over there, nothing more. I waited in the designated space for about 40 minutes before learning from another passenger that I needed to check in again at a specific assistance desk. I was early, so I made it on time to my flight. Your agent should not assume I knew anything, which I didn’t. This was all new, in a recently remodeled space. New to me, anyway.

The ground crew was very good. They communicated clearly and continued updating. The flight crew was fine. The flight crew on the March 20th flight from MCI to Portland was excellent.

Everything ran like it should. Staff was professional. Looking forward to flying with them again.

Process of checking bag, boarding, etc. was all very quick, easy, and streamlined. Only problem I had was the seating: very cramped and uncomfortable, but I suppose that’s the perils of coach. Thankfully it wasn’t a super long flight so it didn’t ruin the experience overall.

SeaTac airport hottible No signage to tell you where to go Took one and half hour to make to gate after being dropped at airport HORRIBLE LOTS OF yelling at patrons EXTREMELY HORRIBLE AND SCARY!

Didn't buy food and did not use entertainment as these were not the purpose of my flight.

Late boarding, but the flight was smooth and the crew was accommodating.

The customer service personnel were excellent. We had pre-ordered two meals but they could only provide one of them; they substituted the meal with a snack at no charge. Flight was on-time.

The flight was delayed almost an hour. No wifi on flight.

Flight was OK, landing not good, boarding was ridiculous. Flight was to load at gate n11 25 minutes before boarding time it was changed to s5 which is 3 tram connections on the other side of the airport, I'm handicapped and even getting a sky cap took 10 minutes needless to say just made it to boarding only because it was delayed. I did learn a valuable lesson don't show up for flight 2 hours early.

We got stuck on the tarmac taxiing after landing early so we didn’t get off the plane until an hour later than we thought we would

Bus to plane was delayed for no apparent reason and our luggage was still on the belt when they shut it off. Took about 20 minutes to turn it back on to get our luggage.

I haven’t flown economy in over 20 years but it was not bad. Room by my feet for my bag and seat was roomy enough. Surprised in a good way.

Second flight in a row where the entertainment system is broken. 5 hour long flight with no entertainment and flight attendants did not seem interested in resolving the matter. Very shocked to be treated this poorly considering I paid for a first class experience and have Diamond Medallion status.

The service from the flight attendants were of supreme quality. They greeted and treated everyone with a wide smile. This is totally absent nowadays. Kudos to them!!!!

The boarding process needs to be refined. Sometimes the gate crew calls out the zones and then flip to showing the.zones boarding on the gate monitor display. So, unless you are huddled around the gate lanes watching the monitor, you could miss your boarding zone. Suggest the zones be announced each time a new zone is allowed to board.

This route with Delta always has delays or is cancelled. Aircrafts seem smaller and older. I fly Delta quite a bit - haven’t had issues with the international flights. But this route has always been the troublesome one

My seat had no padding, it was literally plywood with a plastic cover. I could not change seats on my 10 hour flight. My excitement for this trip helped me deal with the pain.

As we lined up to board they gave our plane to a flight going to Newark. So then we got delayed until they could find another plane. Flight crew was ok. I’m assuming since it’s a shorter flight they only offered water and coffee.

The flights were on time- Great service Would have liked more options for food choices.

Flight was delayed “due to earlier delays of that plane”, so we were nearly three hours late.

Airport terminal was outdated, flight was on a small jet with no wifi

the whole trip was smooth, and as comfortable as flying is these days. flight crew was friendly and very courteous and helpful.

Yet another flight in which beverage and snack service was skipped. Other that that, firmly mediocre. Landed early, to gate late due to congestion at the gates. Airline's fault or airports fault: unknown.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

Excellent flight. Smooth, efficient boarding. Quick flight. Arrived early at STL.

This was a very average flight. The seat was out of alignment so more uncomfortable than usual. The cabin felt not well maintained. But I safely got where I needed to go.

We had a 90 minute delay due to equipment failure that was detected just before we took off. United rebooked my connecting flight.

Dinner was okay but the breakfast was not eatable on the flight San Francisco to Zurich.

Last minute gate change nearly caused us to miss our flight. Change was not announced or displayed in the main board at the old gate. Terrible communication. When we landed we had to wait 20 minutes because there was another plane at the assigned gate. Not the crew’s fault, but adding 20 minutes to a 45 minute flight sucked.

We called Kayak for a change due to the TSA situation in Atlanta. What we got was a canceled return flight (in error) and we had to find the mistake. Not happy with Kayak who blamed it on AA.

Small plane, poor meal choices for first class, bad terminal and boarding experience at LAX

Boarding delayed 20 minutes for no reason, no wifi, in flight entertainment, or snacks / waters?

This flight captain and crew were amazing, started ahead of time of departure and reached 30 mins before arrival time. Amazing!

Improvements in communication and empathy are absolutely necessary for American Airlines staff (top down). It’s like they are numb to the needs of their customers.

I like the speed of boarding and deplaning and the fact that everything was on time. The crew (attendants) were probably quite new and did not begin the in cabin service until 30 min before landing even though there was little to no air turbulence for the last 1.5 hours of the flight. It made for a mad scramble at the end to get trash collected and carts stowed before touch down.

The flights was delayed by hours and it was the firmest landing I have experienced in my life. My back is still sore.

I did like the employee's, they are very friendly and all smiled most of the time, Overall, from checking in bags to getting on plane, not enough employees to be able to get all on the plane, therefore I was not able to get on the plane, due to no one wea there for me to check in my bag, so I decided to go thru the security point and by the time they were done with my bags, I was told that my bag cannot be checked in, and then found out that the lady that does the check in was boarding the customers onto the plane, she said that she was going back and fourth, there for was not able to get on the plane, which changed all my flights by the time I got to Dallas, I was on standby 3 times, and wasn't sure about being able to get on the fourth plane, so ended up buying another plane ticket, so I could make my destination on time.

Not sure about entertainment as I didn't use any, so maybe there should be an NA option on this survey. Otherwise everything was just as it should be. Of course I wish planes were more comfortable and had seats that would tilt back further.

American Airlines “Randy” questioned why I needed preboarding and denied my request for same. Then Randy attempted to berate me when I boarded with my group. I was seated in an exit roll with a young man with a disability that exhibited difficulty controlling and settling himself. But Tandy questioned my disability. The flight was horrible. It was overpacked.

Everything you need to know for your flight from Portland to St. Louis

Information on your arrival and departure airports