Green River State Forest
Green River State Forest is an easy 40+ miles off-road trail near Black Diamond, WA, best run Year-round. No gear is marked required; All-terrain tires, 4WD capability and Tow strap are recommended. A stock high-clearance 4x4 can run it; check the gear list before you go.
Trail Conditions
No reports yet
Green River State Forest is Seattle's backyard off-road playground, offering miles of gravel logging roads through second-growth forest that's regenerated beautifully since the logging days. The forest provides a gentle introduction to off-road driving with well-maintained roads and manageable grades. The Green River Gorge at the forest's edge adds scenic interest, with emerald pools and basalt cliffs creating a surprisingly wild landscape just 45 minutes from downtown Seattle.
Fun Facts
The Green River Gorge was formed by the river cutting through layers of ancient coal deposits.
Black Diamond was once a thriving coal mining town. Old mine entrances are visible along trails.
The forest is managed by the Washington DNR as a working forest for timber and recreation.
🛞 Tires
🔧 Suspension
⚙️ Drivetrain
🪢 Recovery
Closest campgrounds to Green River State Forest:
- Majestic Mobile Manor RV Park · Puyallup · 19 mi (straight-line)
- Snoqualmie River Campground & RV Park · Fall City · 19 mi (straight-line)
- Tinkham Campground · 20 mi (straight-line)
- Tall Chief RV Resort, An Encore Resort · Fall City · 21 mi (straight-line)
- Trailer Inns RV Park – Seattle/Bellevue · Bellevue · 22 mi (straight-line)
- Denny Creek Campground · 25 mi (straight-line)
Straight-line distance. Check the map for drive time.
GPS Coordinates
Import into Gaia GPS, OnX Offroad, or Garmin
Map of Black Diamond, WA
5-Day Forecast
Nearby Trails
WHAT YOU'LL NEED
Stock rigs can usually run this trail, but the right tire size and fitment make it more enjoyable.
Tire Size Calculator
Convert tire sizes and compare diameter differences before you swap.
Verify your stock tires meet minimum clearance for this trail.
Gear Ratio Calculator
Find the right gear ratio after lifting or upsizing tires.
Re-gear after a tire upgrade to restore trail torque and MPG.
Wheel Fitment Calculator
Calculate backspacing and offset so wider wheels clear your suspension.
Ensure any wheel upgrade clears your factory suspension.