American Airlines Flight UA3899 Deals & Information (2025/2026)

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American Airlines Flight 3899 Route Deals From $112

The cheapest prices found with in the last 7 days for return flights were $220 and $112 for one-way flights to O'Hare Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Thu, Oct 2 - Sun, Oct 5
MSO
Missoula Intl.
ORD
O'Hare Intl.
$220 Roundtrip, found 6 hours ago
$220
Roundtrip
found 6 hours ago
Select American Airlines flight, departing Thu, Oct 2 from Missoula Intl. to O'Hare Intl., returning Sun, Oct 5, priced at $220 found 6 hours ago
Thu, Oct 2 - Sun, Oct 5
MSO
Missoula Intl.
ORD
O'Hare Intl.
$295 Roundtrip, found 6 hours ago
$295
Roundtrip
found 6 hours ago
Select American Airlines flight, departing Thu, Oct 2 from Missoula Intl. to O'Hare Intl., returning Sun, Oct 5, priced at $295 found 6 hours ago
Thu, Oct 2 - Sun, Oct 5
MSO
Missoula Intl.
ORD
O'Hare Intl.
$316 Roundtrip, found 6 hours ago
$316
Roundtrip
found 6 hours ago
Select American Airlines flight, departing Thu, Oct 2 from Missoula Intl. to O'Hare Intl., returning Sun, Oct 5, priced at $316 found 6 hours ago