United Flight 639 Deals & Information (2025/2026)

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United Flight 639 Route Deals From $224

The cheapest prices found with in the last 7 days for return flights were $209 and $224 for one-way flights to Missoula Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Thu, May 29 - Sat, May 31
DEN
Denver Intl.
MSO
Missoula Intl.
$209 Roundtrip, found 9 hours ago
$209
Roundtrip
found 9 hours ago
Select United flight, departing Thu, May 29 from Denver Intl. to Missoula Intl., returning Sat, May 31, priced at $209 found 9 hours ago
Fri, May 30 - Sat, May 31
DEN
Denver Intl.
MSO
Missoula Intl.
$213 Roundtrip, found 9 hours ago
$213
Roundtrip
found 9 hours ago
Select United flight, departing Fri, May 30 from Denver Intl. to Missoula Intl., returning Sat, May 31, priced at $213 found 9 hours ago
Wed, Sep 17 - Sat, Sep 20
DEN
Denver Intl.
MSO
Missoula Intl.
$219 Roundtrip, found 4 days ago
$219
Roundtrip
found 4 days ago
Select United flight, departing Wed, Sep 17 from Denver Intl. to Missoula Intl., returning Sat, Sep 20, priced at $219 found 4 days ago
Mon, May 12 - Mon, May 19
DEN
Denver Intl.
MSO
Missoula Intl.
$222 Roundtrip, found 21 hours ago
$222
Roundtrip
found 21 hours ago
Select United flight, departing Mon, May 12 from Denver Intl. to Missoula Intl., returning Mon, May 19, priced at $222 found 21 hours ago
Sat, Jun 14 - Mon, Jun 23
DEN
Denver Intl.
MSO
Missoula Intl.
$223 Roundtrip, found 2 days ago
$223
Roundtrip
found 2 days ago
Select United flight, departing Sat, Jun 14 from Denver Intl. to Missoula Intl., returning Mon, Jun 23, priced at $223 found 2 days ago
Fri, Sep 26 - Tue, Sep 30
DEN
Denver Intl.
MSO
Missoula Intl.
$229 Roundtrip, found 17 hours ago
$229
Roundtrip
found 17 hours ago
Select United flight, departing Fri, Sep 26 from Denver Intl. to Missoula Intl., returning Tue, Sep 30, priced at $229 found 17 hours ago

Frequently asked questions

What route does flight number UA639 take?
UA639 takes a number of routes. The most popular is PBI to Liberty Intl. Airport (EWR), which is a direct flight. This flight takes roughly 2 hours and 43 minutes. However, there may be other flights with this number that have one or more stops.
What kind of plane is on flight number UA639?
UA639 is a flight number that is used on many different routes. If you have a ticket on the most popular one, West Palm Beach, FL Airport (PBI-Palm Beach Intl.) to EWR, there’s a good chance you’ll be on the Boeing 737-900.
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 UA639 flight with Travelocity, please visit our Customer Service Portal.