United Flight 577 Deals & Information (2026/2027)

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United Flight 577 Route Deals From $123

The cheapest prices found with in the last 7 days for return flights were $319 and $123 for one-way flights to Newark Liberty Intl. Airport for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, Nov 10 - Fri, Nov 13
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$319 Roundtrip, found 5 days ago
$319
Roundtrip
found 5 days ago
Select United flight, departing Tue, Nov 10 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Fri, Nov 13, priced at $319 found 5 days ago
Tue, Nov 10 - Fri, Nov 13
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$329 Roundtrip, found 5 days ago
$329
Roundtrip
found 5 days ago
Select United flight, departing Tue, Nov 10 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Fri, Nov 13, priced at $329 found 5 days ago
Tue, Nov 10 - Sun, Nov 15
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$342 Roundtrip, found 4 hours ago
$342
Roundtrip
found 4 hours ago
Select United flight, departing Tue, Nov 10 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Sun, Nov 15, priced at $342 found 4 hours ago
Tue, Nov 10 - Sun, Nov 15
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$352 Roundtrip, found 4 hours ago
$352
Roundtrip
found 4 hours ago
Select United flight, departing Tue, Nov 10 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Sun, Nov 15, priced at $352 found 4 hours ago
Fri, Dec 25 - Mon, Dec 28
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$361 Roundtrip, found 3 hours ago
$361
Roundtrip
found 3 hours ago
Select United flight, departing Fri, Dec 25 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Dec 28, priced at $361 found 3 hours ago

Frequently asked questions

What route does flight number UA577 take?
UA577 travels from DEN to GEG directly. This service generally takes 2 hours and 24 minutes.
How often is UA577 on time?
Roughly 90% of UA577 flights arrive according to scheduled times — so if you're jetting from Denver, CO Airport (DEN-Denver Intl.) to GEG, you can be confident that you'll touch down at your destination ASAP. In the rare event that your United Airlines trip is delayed, you can expect to wait about 8 minutes. Because of the air carrier's top-notch service, this route has a star rating of 4.6.
What kind of plane is on flight number UA577?
The Boeing 737-800 is the kind of plane that's mostly used for flight number UA577. This flight almost always sets off from DEN and comes in to land at GEG.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA577 flight with Travelocity, please visit our Customer Service Portal.