Federal Way, WA to Grand Coulee, WA is 232.9 miles and takes about 4h 46m via I 90, with a fuel budget near $49 and enough daylight to finish in a day. This trip stays within Washington state, beginning in the Pacific Coast region and ending in the same region. Expect a largely highway experience for most of the drive. With a total duration under five hours and a moderate fuel cost, this is a straightforward, single-day excursion.
Trip Pace
Same-day drive is realistic
A same-day return is possible, but it will make for a full day on the road.
Break Rhythm
1 planned break
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
116.5 miles from Federal Way, WA
A natural place for your longest stop of the day
, about 2h 16m into the drive
.
Main Roads
Road
Distance
Duration
I 90
125.5 mi
2h 16m
Coulee Boulevard
25.1 mi
32m
State Route 18
24.4 mi
31m
WA 17
21.3 mi
29m
WA 283
20 mi
26m
Coulee Corridor / Sunset Highway
4.3 mi
6m
WA 28
3.7 mi
5m
South Peasley Canyon Road
1.8 mi
3m
Longest stretch:
I 90
— 125.5 mi, about 2h 16m
Traffic on I-90
Hour-of-day weekday pattern from 35 FHWA count stations on your route.
Peak
1 PM
~1,207 veh/hr typical
· worst 2,108
Quietest
2 AM
~99 veh/hr
Peak-to-quiet ratio
12.2×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 52 weeks of 2023 FHWA Travel Monitoring Analysis System data. Weekday hours only (Mon–Fri).
Turn-by-Turn Driving Directions
Step-by-step road directions between Federal Way, WA and Grand Coulee, WA.
1
Start on this road
24 ft·7 sec·this road
2
Turn left onto South 312th Street
158 ft·5 sec·South 312th Street
3
Turn left onto WA 99
0.5 mi·1 min·Pacific Highway South
4
Turn left onto South 320th Street
1.4 mi·3 min·South 320th Street
Use the straight lane.
5
Continue on South Peasley Canyon Road
1.0 mi·1 min·South Peasley Canyon Road
6
Enter roundabout onto South Peasley Canyon Road
95 ft·1 sec·South Peasley Canyon Road
7
Continue on South Peasley Canyon Road
0.7 mi·1 min·South Peasley Canyon Road
8
Turn left onto West Valley Highway North
334 ft·10 sec·West Valley Highway North
Use the left lane.
9
Take the ramp
0.2 mi·28 sec
Toward WA 18 East, WA 167 North: Renton, North BendUse the right lane.
10
Keep slight left at fork
0.2 mi·30 sec
Toward WA 18 East
11
Merge onto WA 18
24 mi·31 min·State Route 18
Use the straight / slight right lanes.
12
Continue on WA 18
0.1 mi·8 sec·Snoqualmie Parkway
13
Take the exit
0.6 mi·1 min
Toward I 90 East: Spokane
14
Merge onto I 90
126 mi·2 hr 16 min·I 90
Use the straight / slight right lanes.
15
Take the exit
0.5 mi·1 min
Toward WA 283 North: Ephrata, Soap Lake
16
Continue on WA 281 Spur
0.1 mi·9 sec·Burke Spur
17
Turn right onto WA 283
20 mi·26 min·WA 283
18
Turn right onto 5th Avenue Southwest
392 ft·14 sec·5th Avenue Southwest
19
Turn left onto Alder Street Southwest
0.4 mi·55 sec·Alder Street Southwest
20
Continue on Alder Street Northwest
1.6 mi·2 min·Alder Street Northwest
21
Turn right onto WA 28
3.7 mi·5 min·WA 28
22
Turn left onto WA 17
21 mi·29 min·WA 17
23
At end of road, turn right onto US 2
4.3 mi·6 min·Coulee Corridor / Sunset Highway
24
Continue on WA 155
25 mi·32 min·Coulee Boulevard
25
Continue on WA 155
0.5 mi·56 sec·Grand Coulee Avenue
26
Continue on WA 155
0.4 mi·1 min·Midway Avenue
27
Turn right onto Spokane Way
19 ft·0 sec·Spokane Way
28
Arrive at destination
Spokane Way
Trip Plan
Given the manageable 4h 46m duration, leaving Federal Way in the morning allows ample time to reach Grand Coulee before evening. The drive is primarily on I 90, so keep an eye on your fuel levels, especially as you approach the estimated $49 cost, as services can be spaced out on interstates. You'll have one major stretch of 125.5 miles on I 90, so plan a break before or after that segment. The final portion of the trip will be on surface roads.
Morning Departure
An early start around 7-8 AM gets you there with plenty of daylight left.
Evening Departure
A late afternoon start means arriving after dark. Morning is better.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 116.5 miles from Federal Way, WA, or about 2h 16m into the drive.
The longest continuous stretch on this route runs about 125.5 miles.
This is a comfortable same-day trip.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 51 miles or 1h 5m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 116.5 miles or 2h 16m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 3h 49m
Traffic, exits, and arrival timing usually matter more near Grand Coulee, WA than in the middle of the route.
Before You Leave
+
Open the route before leaving Federal Way, WA 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.
Day 1
Settle into the route from Federal Way, WA
This is one driving day of about 232.9 miles and 4h 46m.
Your first comfortable stop window is around 51 miles from Federal Way, WA.
This route can stay practical as a one-day drive if traffic stays reasonable.
Plan about 1 real break rather than only quick fuel stops.
The longest stretch is on I 90 for about 125.5 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Place data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 16
5 decision points cluster between mile 0 and 4.3 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
5
0 mi into trip|~0m in|South 312th Street
Turn left onto South 312th Street
Navigation decision point
5
3.7 mi into trip|~7m in|West Valley Highway North
Turn left onto West Valley Highway North
Lane positioning matters here
Use the left lane.
8
3.8 mi into trip|~8m in
Take the ramp toward WA 18 East, WA 167 North: Renton, North Bend
Lane positioning matters here. Multiple destination signs - pick the right one
Use the right lane.
Toward WA 18 East, WA 167 North: Renton, North...
6
4 mi into trip|~8m in
Keep slight left at fork toward WA 18 East
Highway fork - watch signs carefully
Toward WA 18 East
5
4.3 mi into trip|~9m in|WA 18 / State Route 18
Merge onto WA 18 / State Route 18
Merge point - match speed before joining. Lane positioning matters here
Use the straight / slight right lanes.
Fuel & Cost
Regular Gas
$45.37 one way
$90.74 round trip
$4.95/gal25.4 MPG avg82 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$5.18
$47.53
$95.07
premium
$5.39
$49.43
$98.86
diesel
$4.80
$43.98
$87.95
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$45
Meals
$25–$50
Total
$70–$95
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 81.5 kg one way.
Prices: EIA weekly data, 2026-07-13.
Driving Electric?
About $24 in charging
· 0 stops
· 67% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
69.9
0
$24.45
$11.18
Efficient EV
58.2
0
$20.38
$9.32
EV Truck/SUV
93.2
1
$32.61
$14.91
Gas CO2
81 kg
EV CO2
27 kg (67% less)
Plan for 0 charging stops, roughly every 270 miles. Allow 25-40 minutes per stop at a DC fast charger.
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.
Forecast as of Jul 18, 2026
Origin
Federal Way, WA
Morning
in Federal Way on Sunday
Local time
11:53 AM
PDT
Current temp
78°F
Mostly Sunny
W 5 mph1% chanceLive forecast
Red Flag Warning
Red Flag Warning issued July 17 at 9:08PM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Red Flag Warning
Red Flag Warning issued July 17 at 9:08PM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Destination
Grand Coulee, WA
Morning
in Grand Coulee on Sunday
Local time
11:53 AM
PDT
Current temp
93°F
Sunny
SW 6 to 15 mph0% chanceLive forecast
Red Flag Warning
Red Flag Warning issued July 17 at 9:08PM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Red Flag Warning
Red Flag Warning issued July 17 at 9:08PM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
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.
Time zone
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
15 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
4h 46m on the road
An early start around 7-8 AM gets you there with plenty of daylight left.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
National Parks Near This Route
Worth a detour if your schedule allows.
Klondike Gold Rush - Seattle Unit National Historical Park
National Historical Park
Seattle flourished during and after the Klondike Gold Rush. Merchants supplied people from around the world passing through this port city on their way to a remarkable adventure in the Yukon Territory...
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
You'll be on the highway for 84% of this 232.9-mile drive. The longest continuous stretch on a single road is 125.5 miles on I 90. After this, you'll transition to surface roads, including Coulee Boulevard and State Route 18, for the remaining miles. Expect to notice more frequent exits and potentially slower speeds as you move off the main interstate.
84% highway — fuel and pacing are the main things to plan.
28 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 125.5 mi on I 90.
How Hard Is This Drive?
5/10
This is a straightforward highway drive that stays mostly on I 90 and Coulee Boulevard. You will hit about 16 points where you need to pay attention to lane position or signs. The trickiest moment comes early in the drive near South 312th Street.
Driving Effort5/10
Moderate - straightforward overall, but long enough or busy enough to require pacing
Balances navigation complexity with total wheel time.
This drive requires moderate attention. Across 232.9 miles you will encounter 16 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
Where does it get tricky?
The main spots that need attention: near the start (South 312th Street): Navigation decision point; at 3.7 miles (West Valley Highway North): Lane positioning matters here; at 3.8 miles: Lane positioning matters here. Multiple destination signs - pick the right one.
Elevation Profile
Gently rolling terrain
2,394 ft415 ft
Total Climb
2,867 ft
Total Descent
1,862 ft
Highest Point
2,394 ft
~66.5 mi in
Elevation Range
1,979 ft
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
On the drive from Federal Way, WA to Grand Coulee, WA, road signs begin pointing toward Soap Lake along the way.
Federal Way is a city in King County on the Puget Sound of Washington State. It is the home of the Pacific Bonsai Museum and Rhododendron Species Botanical Gardens. With a population of 96,000 (2016), Federal Way is one of Seattle's largest suburbs.
Top landmarks
•Wild Waves Theme Park — amusement park and water park in Federal Way, Washington, United States
Grand Coulee is a city in the Columbia River Plateau of Washington State. It is on the shore of Lake Roosevelt just above the Grand Coulee Dam, the largest hydroelectric power producer in the United States.
This guide includes the neighboring communities of Electric City and Coulee Dam.
Doable as a same-day drive at 4h 46m. Total distance: 232.9 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
4h 46m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (84%). Some complex stretches to watch for.
Frequently Asked Questions
The longest stretch is about 125.5 miles on I 90. The full list of main roads is in the Roads section above.
Yes — we found about 10 rest areas or service plazas within a short detour of the route (from OpenStreetMap). See the Rest Stops tab under Nearby Places for locations and mile markers. Plan to stretch, use the bathroom, and top off fluids every 2–3 hours on longer drives.
Yes, with realistic expectations. Build in a stop roughly every 2 hours, have snacks and activities ready, and check the Nearby Places tabs for kid-friendly stops along the way.
The main spots that need attention: near the start (South 312th Street): Navigation decision point; at 3.7 miles (West Valley Highway North): Lane positioning matters here; at 3.8 miles: Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — Klondike Gold Rush - Seattle Unit National Historical Park. See the National Parks section for detour distances and tips on detours.
Possible but tiring. At 4.8 hours each way, an in-and-out day trip would put you behind the wheel for 9.5 hours — manageable with a long break at Grand Coulee, WA, but most travelers stay overnight.
