Origin
Saint Maries, ID
Late night in Saint Maries on Saturday
Local time
12:06 AM
PDT
Current temp
44°F
Unavailable
Live forecast
Trip from Saint Maries, ID to Idaho Falls, ID
Compiled and reviewed by the Trip.ovh planning team at COD Solutions Oy · Last reviewed Apr 18, 2026 · Editorial standards
Drive Time
8h 17m
Distance
491 mi
790 km
Drive Score
8/10
Great drive
Same Day?
2-day trip
Fuel Cost
$78
one way
EV Charging
Unknown
Best Time to Leave
4 AM
8h 10m
★
6 AM
8h 18m
8 AM
8h 33m
10 AM
8h 23m
12 PM
8h 22m
3 PM
8h 24m
5 PM
8h 32m
8 PM
8h 13m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Saint Maries, ID
Sami Aksu
Idaho Falls, ID
Wikimedia Commons
Trip Overview
The drive from Saint Maries, ID to Idaho Falls, ID covers 491 miles and takes about 8h 17m behind the wheel. It usually feels better as a 2-day road trip than as one long push.
The route leans on I 90, I 15, South Highway 3 for much of the mileage, and the overall profile is highway-focused drive. The longest uninterrupted segment is about 256.2 miles on I 90. At current regular gas prices, budget about $77.81 one way before food or hotel costs.
Trip Pace
Best split across 2 days
Treat the return leg as its own travel day rather than an afterthought.
Break Rhythm
2 planned breaks
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
245.5 miles from Saint Maries, ID
A natural place for your longest stop of the day , about 4h 19m into the drive .
Who Is This Route For?
Family Friendly
Moderate complexity with 2 natural rest stops along the way.
Solo Traveler
8h 17m drive, plan rest stops for pacing.
First-Time Driver
Mostly highway driving (99%). Straightforward navigation.
Drive Character
This is a 8h 17m highway drive covering 491 miles, with most of the trip on I 90 and I 15. The longest continuous stretch is about 256.2 miles on I 90.
Most of the miles stay on highways, which makes pacing and fuel planning easier than turn-by-turn city driving.
There are about 20 navigation steps in the underlying route data, so the final approach matters more than the middle miles.
I 90 is the longest continuous segment at about 256.2 miles.
How Hard Is This Drive?
This is a straightforward highway drive that stays mostly on I 90 and I 15. There are only a few real navigation decisions along the way. The trickiest moment comes early in the drive near South 3rd Street.
Driving Effort
4/10
Easy - simple navigation with a manageable amount of wheel time
Balances navigation complexity with total wheel time.
The route itself is not hard, but at 8h 17m, endurance matters. Plan breaks every 2-3 hours. The 13 decision points are all manageable with basic attention.
Where does it get tricky?
The main spots that need attention: near the start (South 3rd Street): Navigation decision point; at 289 miles: Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one; at 487.5 miles (I 15 BUS; US 20): Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one.
Critical Maneuvers
5 of 13 key pointsThese are the spots where you need to pay the most attention. Preview them before you drive.
5
0 mi into trip
|
~0m in
|
South 3rd Street
Turn left onto South 3rd Street
Navigation decision point
5
289 mi into trip
|
~5h 3m in
Take the exit toward I 15 South: Dillon, Idaho Falls
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Toward I 15 South: Dillon, Idaho Falls
5
487.5 mi into trip
|
~8h 10m in
|
I 15 BUS; US 20
Take the exit onto I 15 BUS; US 20 toward I 15 Business, US 20 West: Historic Downtown, Arco
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Toward I 15 Business, US 20 West: Historic Down...
5
490.9 mi into trip
|
~8h 17m in
|
West Stone Run Lane
Turn right onto West Stone Run Lane
Navigation decision point
5
490.9 mi into trip
|
~8h 17m in
|
Charleston Lane
Turn left onto Charleston Lane
Navigation decision point
Main Roads
| Road | Distance | Duration |
|---|---|---|
| I 90 | 256.2 mi | 4h 13m |
| I 15 | 198 mi | 3h 5m |
| South Highway 3 | 21.8 mi | 32m |
| Highway 3 North | 10.7 mi | 15m |
| South Boulevard | 1 mi | 2m |
| South Utah Avenue | 0.6 mi | 1m |
| West 17th Street | 0.6 mi | <1m |
| West Broadway Street | 0.4 mi | <1m |
Longest stretch:
I 90
— 256.2 mi, about 4h 13m
Turn-by-Turn Driving Directions
Step-by-step road directions between Saint Maries, ID and Idaho Falls, ID.
1
Start on West Jefferson Avenue
49 ft
·
7 sec
·
West Jefferson Avenue
2
Turn left onto South 3rd Street
0.2 mi
·
26 sec
·
South 3rd Street
3
Continue on ID 3
11 mi
·
15 min
·
Highway 3 North
4
Continue on ID 3
22 mi
·
32 min
·
South Highway 3
5
Take the ramp
0.2 mi
·
28 sec
6
Merge onto I 90
256 mi
·
4 hr 13 min
·
I 90
7
Take the exit
0.5 mi
·
1 min
Toward I 15 South: Dillon, Idaho Falls
8
Merge onto I 15
198 mi
·
3 hr 5 min
·
I 15
9
Take the exit onto I 15 BUS; US 20
0.3 mi
·
46 sec
·
I 15 BUS; US 20
Toward I 15 Business, US 20 West: Historic Downtown, Arco
10
Continue on I 15 BUS; US 20
0.4 mi
·
54 sec
·
West Broadway Street
11
Turn right onto South Utah Avenue
0.5 mi
·
50 sec
·
South Utah Avenue
12
Enter roundabout onto South Utah Avenue
103 ft
·
2 sec
·
South Utah Avenue
13
Continue on South Utah Avenue
0.1 mi
·
23 sec
·
South Utah Avenue
14
Turn left onto Pancheri Drive
0.4 mi
·
42 sec
·
Pancheri Drive
15
Continue on West 17th Street
0.6 mi
·
57 sec
·
West 17th Street
16
Turn right onto South Boulevard
1.0 mi
·
2 min
·
South Boulevard
17
Continue on Stonebrook Lane
466 ft
·
14 sec
·
Stonebrook Lane
18
Turn right onto West Stone Run Lane
241 ft
·
16 sec
·
West Stone Run Lane
19
Turn left onto Charleston Lane
152 ft
·
6 sec
·
Charleston Lane
20
Arrive at destination
Charleston Lane
Trip Plan
Morning Departure
Start early — leave by 6-7 AM to arrive at a reasonable hour.
Evening Departure
This is a long drive — plan for a morning departure or consider splitting it into two days.
This drive is better paced as a 2-day trip.
Plan roughly 2 meaningful breaks for fuel, food, and rest.
The halfway point lands around 245.5 miles from Saint Maries, ID, or about 4h 19m into the drive.
The longest continuous stretch on this route runs about 256.2 miles.
Consider an overnight stop or starting very early.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 108 miles or 2h 3m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 245.5 miles or 4h 19m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Overnight split
Day 1 wrap after about 245.5 miles or 4h 19m
Stop before fatigue turns the last few hours into a grind. You want day two to start fresh, not just resumed.
Final approach
Final hour starts around 7h 17m
Traffic, exits, and arrival timing usually matter more near Idaho Falls, ID than in the middle of the route.
Before You Leave
+
Open the route before leaving Saint Maries, ID so your first major turns are already loaded.
+
Leave with enough water and a charging cable within reach, not packed away.
+
Check your fuel range against the first long segment, especially if you are starting outside city service areas.
+
Pick one backup stop option before the midpoint in case traffic changes your pacing.
+
Treat this as a 2-day road trip and book the overnight stop before the busiest arrival window.
Day 1
Settle into the route from Saint Maries, ID
Aim for roughly 246 miles and 4.1 hours of wheel time on this day.
Day 2
Finish the approach into Idaho Falls, ID
Aim for roughly 246 miles and 4.1 hours of wheel time on this day.
Your first comfortable stop window is around 108 miles from Saint Maries, ID.
This route usually feels better as a 2-day drive than as one long push.
Plan about 2 real breaks rather than only quick fuel stops.
The longest stretch is on I 90 for about 256.2 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Halfway Point
Midpoint
About 245.5 mi from Saint Maries, ID · 4h 19m into the drive
Mid-route town
Overnight candidate
246 mi into the route
Best for: Hotel check-in, dinner, and a fresh start
This lines up well with a realistic day-end stop if you are breaking the drive into stages.
Find hotels in Thompson Falls, MTOvernight Options
Night 1
246 mi · about 4.1h in
A practical overnight split lands near Thompson Falls, MT after about 246 miles or 4.1 hours of driving.
Find hotelsPacing Suggestions
Fuel and coffee
A short stop after about 108 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 245.5 miles from Saint Maries, ID, which is a good place for a longer meal and fuel stop.
Before the longest stretch
Fuel checkTop up before I 90 if your tank is already low. That segment runs about 256.2 miles.
Overnight split
Hotel stopFor a steadier pace, wrap day one after about 246 miles or 4.1 hours on the road.
Arriving in Idaho Falls, ID
The final approach into Idaho Falls, ID usually feels slower than the middle of the drive, so avoid planning your tightest schedule at the very end.
Try to arrive with enough fuel left to skip an immediate station stop unless you already know the area around Idaho Falls, ID.
On a multi-day trip, keep the last day a little lighter so you reach Idaho Falls, ID with some flexibility left in the schedule.
After long uninterrupted mileage, take five minutes before the last urban segment to reset and refocus on exits, merges, and city traffic.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Fuel & Cost
Regular Gas
$77.81 one way
$155.61 round trip
$4.03/gal
25.4 MPG avg
172 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.22 | $81.56 | $163.11 |
| premium | $4.53 | $87.59 | $175.17 |
| diesel | $5.61 | $108.41 | $216.81 |
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$78
Hotel (1n)
$80–$140
Meals
$50–$100
Total
$208–$318
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 171.8 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $52 in charging · 1 stop · 67% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 147.3 | 1 | $51.55 | $23.57 |
| Efficient EV | 122.8 | 1 | $42.96 | $19.64 |
| EV Truck/SUV | 196.4 | 2 | $68.74 | $31.42 |
Gas CO2
172 kg
EV CO2
57 kg (67% less)
Plan for 1 charging stop. A 30-minute DC fast charge mid-route should be enough to complete the trip comfortably.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Destination
Idaho Falls, ID
Late night in Idaho Falls on Saturday
Local time
1:06 AM
MDT
Current temp
63°F
Unavailable
Live forecast
Seasonal Notes
Summer travel usually means heavier construction, hotter rest stops, and busier weekend traffic around major cities.
Winter travel shortens daylight, so a route that looks manageable on paper can feel much longer after dark.
Holiday weekends tend to make both departure and arrival windows slower than the raw route time suggests.
For long drives, weather on day two can matter just as much as conditions at departure, so check the whole travel window rather than only the first day.
Time zone
1 hour later
The destination clock does not match departure time, so double-check hotel check-in windows and late arrival plans.
Temperature spread
19 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
8h 17m on the road
This is long enough that the arrival forecast matters almost as much as departure conditions. Recheck both ends before you roll.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
Frequently Asked Questions
The drive from Saint Maries, ID to Idaho Falls, ID covers 491 miles and takes about 8h 17m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are I 90, I 15, South Highway 3. Most of the drive stays on highways, so watch for ramps and exits.
Consider an overnight stop or starting very early.
Yes. This route is usually more comfortable as a 2-day drive. A sensible stopping point is after roughly 246 miles on day one.
The midpoint is about 245.5 miles from Saint Maries, ID. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $77.81 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
Start early — leave by 6-7 AM to arrive at a reasonable hour. This is a long drive — plan for a morning departure or consider splitting it into two days.
Plan about 2 meaningful breaks for fuel, food, or rest. Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
The route itself is not hard, but at 8h 17m, endurance matters. Plan breaks every 2-3 hours. The 13 decision points are all manageable with basic attention.
The main spots that need attention: near the start (South 3rd Street): Navigation decision point; at 289 miles: Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one; at 487.5 miles (I 15 BUS; US 20): Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one.
The route from Saint Maries, ID to Idaho Falls, ID does not surface many named destination signs beyond the main corridor.
How this page is built
Compiled by the Trip.ovh planning team at COD Solutions Oy from open government datasets — OSRM over OpenStreetMap for geometry, and EIA for fuel prices. See our methodology for refresh cadence and limitations.
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