United Flight 577 Deals & Information (2026/2027)

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United Flight 577 Route Deals From $147

The cheapest prices found with in the last 7 days for return flights were $293 and $147 for one-way flights to Newark Liberty Intl. Airport for the period specified. Prices and availability are subject to change. Additional terms apply.

Fri, Dec 11 - Mon, Dec 14
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$293 Roundtrip, found 20 hours ago
$293
Roundtrip
found 20 hours ago
Select United flight, departing Fri, Dec 11 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Dec 14, priced at $293 found 20 hours ago
Tue, Nov 10 - Thu, Nov 12
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$303 Roundtrip, found 2 days ago
$303
Roundtrip
found 2 days ago
Select United flight, departing Tue, Nov 10 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Thu, Nov 12, priced at $303 found 2 days ago
Fri, Dec 11 - Mon, Dec 14
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$309 Roundtrip, found 20 hours ago
$309
Roundtrip
found 20 hours ago
Select United flight, departing Fri, Dec 11 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Dec 14, priced at $309 found 20 hours ago
Thu, Nov 12 - Sat, Nov 14
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$313 Roundtrip, found 3 days ago
$313
Roundtrip
found 3 days ago
Select United flight, departing Thu, Nov 12 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Sat, Nov 14, priced at $313 found 3 days ago
Fri, Dec 4 - Wed, Dec 9
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$314 Roundtrip, found 5 days ago
$314
Roundtrip
found 5 days ago
Select United flight, departing Fri, Dec 4 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Wed, Dec 9, priced at $314 found 5 days ago
Mon, Nov 2 - Mon, Nov 9
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$318 Roundtrip, found 3 days ago
$318
Roundtrip
found 3 days ago
Select United flight, departing Mon, Nov 2 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Nov 9, priced at $318 found 3 days ago
Tue, Jan 5 - Mon, Jan 18
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$319 Roundtrip, found 1 day ago
$319
Roundtrip
found 1 day ago
Select United flight, departing Tue, Jan 5 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Jan 18, priced at $319 found 1 day ago
Fri, Dec 4 - Mon, Dec 7
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$322 Roundtrip, found 2 days ago
$322
Roundtrip
found 2 days ago
Select United flight, departing Fri, Dec 4 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Dec 7, priced at $322 found 2 days ago
Thu, Nov 12 - Sat, Nov 14
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$323 Roundtrip, found 3 days ago
$323
Roundtrip
found 3 days ago
Select United flight, departing Thu, Nov 12 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Sat, Nov 14, priced at $323 found 3 days ago
Fri, Dec 4 - Mon, Dec 7
STL
Lambert-St. Louis Intl.
EWR
Newark Liberty Intl. Airport
$325 Roundtrip, found 2 days ago
$325
Roundtrip
found 2 days ago
Select United flight, departing Fri, Dec 4 from Lambert-St. Louis Intl. to Newark Liberty Intl. Airport, returning Mon, Dec 7, priced at $325 found 2 days 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.