$187 Cheap Flights from Santa Rosa (STS) to Helena (HLN)

View $187 flight on Wed, Oct 22, 2025Opens in a new window

Popular airlines from Santa Rosa, CA (STS-Sonoma County) to Helena, MT (HLN-Helena Regional)

Cheap Flights from Santa Rosa to Helena (STS-HLN)

Prices were available within the past 7 days and start at $187 for one-way flights and $313 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Hawaiian Airlines
Tue, Oct 7 - Tue, Oct 21
STS
Santa Rosa
HLN
Helena
$313 Roundtrip, found 5 days ago
$313
Roundtrip
found 5 days ago
Select Hawaiian Airlines flight, departing Tue, Oct 7 from Santa Rosa to Helena, returning Tue, Oct 21, priced at $313 found 5 days ago
Alaska Airlines
Tue, Oct 7 - Wed, Oct 29
STS
Santa Rosa
HLN
Helena
$322 Roundtrip, found 5 days ago
$322
Roundtrip
found 5 days ago
Select Alaska Airlines flight, departing Tue, Oct 7 from Santa Rosa to Helena, returning Wed, Oct 29, priced at $322 found 5 days ago
Alaska Airlines
Tue, Oct 14 - Wed, Oct 29
STS
Santa Rosa
HLN
Helena
$332 Roundtrip, found 5 days ago
$332
Roundtrip
found 5 days ago
Select Alaska Airlines flight, departing Tue, Oct 14 from Santa Rosa to Helena, returning Wed, Oct 29, priced at $332 found 5 days ago
Alaska Airlines
Wed, Oct 15 - Wed, Oct 29
STS
Santa Rosa
HLN
Helena
$342 Roundtrip, found 5 days ago
$342
Roundtrip
found 5 days ago
Select Alaska Airlines flight, departing Wed, Oct 15 from Santa Rosa to Helena, returning Wed, Oct 29, priced at $342 found 5 days ago
Alaska Airlines
Wed, Oct 8 - Wed, Oct 29
STS
Santa Rosa
HLN
Helena
$352 Roundtrip, found 5 days ago
$352
Roundtrip
found 5 days ago
Select Alaska Airlines flight, departing Wed, Oct 8 from Santa Rosa to Helena, returning Wed, Oct 29, priced at $352 found 5 days ago
Hawaiian Airlines
Tue, Oct 7 - Sat, Oct 11
STS
Santa Rosa
HLN
Helena
$361 Roundtrip, found 5 days ago
$361
Roundtrip
found 5 days ago
Select Hawaiian Airlines flight, departing Tue, Oct 7 from Santa Rosa to Helena, returning Sat, Oct 11, priced at $361 found 5 days ago
Alaska Airlines
Fri, Oct 10 - Wed, Oct 29
STS
Santa Rosa
HLN
Helena
$362 Roundtrip, found 5 days ago
$362
Roundtrip
found 5 days ago
Select Alaska Airlines flight, departing Fri, Oct 10 from Santa Rosa to Helena, returning Wed, Oct 29, priced at $362 found 5 days ago
Hawaiian Airlines
Tue, Oct 7 - Sun, Oct 19
STS
Santa Rosa
HLN
Helena
$363 Roundtrip, found 5 days ago
$363
Roundtrip
found 5 days ago
Select Hawaiian Airlines flight, departing Tue, Oct 7 from Santa Rosa to Helena, returning Sun, Oct 19, priced at $363 found 5 days ago
Hawaiian Airlines
Wed, Oct 8 - Fri, Oct 17
STS
Santa Rosa
HLN
Helena
$372 Roundtrip, found 5 days ago
$372
Roundtrip
found 5 days ago
Select Hawaiian Airlines flight, departing Wed, Oct 8 from Santa Rosa to Helena, returning Fri, Oct 17, priced at $372 found 5 days ago
Hawaiian Airlines
Tue, Oct 14 - Sun, Oct 19
STS
Santa Rosa
HLN
Helena
$373 Roundtrip, found 5 days ago
$373
Roundtrip
found 5 days ago
Select Hawaiian Airlines flight, departing Tue, Oct 14 from Santa Rosa to Helena, returning Sun, Oct 19, priced at $373 found 5 days ago
Flights from Santa Rosa (STS) to Helena (HLN)
Origin airport
Sonoma County
Destination airport
Helena Regional
Roundtrip price
$312
Distance
783 mi

Santa Rosa to Helena Flights

The cheapest times to fly from Santa Rosa to Helena

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Santa Rosa to Helena are during the month of October. You can find some of the cheapest flights from Santa Rosa to Helena with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Santa Rosa to Helena

Sunday is one of the best days to book for cheap flights from Santa Rosa to Helena: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Santa Rosa to Helena

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Santa Rosa to Helena in 2025. You can also book with separate airlines for your outbound and return journeys, from $187 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Santa Rosa to Helena flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Santa Rosa to Helena airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Sonoma County Airport (STS) to Helena Regional Airport (HLN) cost?
Secure a cheap one-way flight from $187 or cheap return flight from $313 from Sonoma County Airport (STS) to Helena Regional Airport (HLN) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight deals on this route.
What is the cheapest month to fly from Sonoma County Airport (STS) to Helena Regional Airport (HLN)?
The cheapest month to fly from STS to HLN is October, when there's less demand. Off-peak season is typically when airlines offer better prices between these airports.
What is the cheapest airline that flies from Sonoma County Airport (STS) to Helena Regional Airport (HLN)?
Use the filter tool on Expedia to compare different airlines and find the most affordable carrier that'll take you from STS to HLN. Then, sort your results by "Price (lowest to highest)" to score a great deal.
How many flights per day from Sonoma County Airport (STS) to Helena Regional Airport (HLN)?
Nonstop flights from Sonoma County Airport (STS) to Helena Regional Airport (HLN) aren't available daily, so you'll need to take a flight with a layover. Explore your options with Expedia's filter tool. Enter your travel dates and click on either "1 Stop" or "2+ Stops."
What day of the week has the most flights from STS to HLN?
Friday is usually the busiest day for flights, while Tuesday tends to be the quietest.* Remember that flight schedules can vary depending on a number of factors, such as the season and airline.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Sonoma County Airport (STS) to Helena Regional Airport (HLN)?
To touch down at Helena Regional Airport (HLN) on time, pick a flight that leaves Sonoma County Airport (STS) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this hour.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Sonoma County Airport (STS) to Helena Regional Airport (HLN) last-minute?
Booking your plane ticket from STS to HLN right before your getaway is generally more expensive. But if you're flexible with your itinerary, you could bag a cheap last-minute fare.
Is it cheaper to book a STS to HLN flight and hotel package?
Compared with arranging hotels and flights separately, booking a STS to HLN flight and hotel package with Expedia could lead to significant savings. Better still, having it all in one place will take the hassle out of travel planning. Simply secure your flights and choose from our extensive range of stays, then tailor your trip with extras like activities and car rentals.
Can I cancel or change the date of my flight from Sonoma County Airport (STS) to Helena Regional Airport (HLN)?
If you reserved your STS to HLN flight in the last 24 hours, you may be able to cancel or modify it without fees. Depending on the airline and the type of fare you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal if you want more information.

Explore a world of travel with Expedia

*Available to One Key members.