$140 Cheap Delta flights St. Louis (STL) to Idaho Falls (IDA)

Landing cheap one-way Delta Air Lines flights from STL to IDA from $140 on Expedia is simple --- just filter by "Price (lowest to highest)." Or check out our affordable return fares from $279 for your next break.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Search for affordable Delta Air Lines flights from Lambert-St. Louis Intl. Airport (STL) to Idaho Falls Regional Airport (IDA) one to three months ahead of your departure date. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. No matter the fare class and journey, the best day to book a domestic flight is usually Sunday and the most expensive day is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book on a Monday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Find Delta Air Lines's earliest flights from STL to IDA by checking the "Morning" and "Early Morning" filters. Not only will you arrive at your destination sooner, early departures also experience 20% fewer cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

Heading from STL to IDA with Delta Air Lines means enjoying a host of benefits, such as a rewarding loyalty program and an excellent in-flight experience. Plus, when booking through Expedia, One Key™ members can collect OneKeyCash™* to redeem on select future travel purchases. That's in addition to the Delta SkyMiles points you can earn with Delta Air Lines.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.