Bob Marshall Wilderness Access
Bob Marshall Wilderness Access is a hard 80+ miles off-road trail near Augusta, MT. It requires a properly built 4x4 with 33"+ all-terrain tires, 4WD with low range, Recovery straps and is best run July - September. Stock trucks and Jeeps are not recommended; plan on the required modifications before attempting it.
Trail Conditions
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The Bob Marshall Wilderness is Montana's crown jewel, the largest wilderness complex in the lower 48 states. While vehicles can't enter the wilderness itself, the access roads through the surrounding national forest are adventure drives in their own right, climbing through grizzly country to remote trailheads where the modern world simply ends. The legendary Chinese Wall limestone escarpment rises 1,000 feet above the surrounding terrain.
Fun Facts
The Bob Marshall Wilderness Complex encompasses over 1.5 million acres, larger than the state of Delaware.
The Chinese Wall is a 1,000-foot limestone escarpment running 22 miles along the Continental Divide.
The area was named after Bob Marshall, a forester and wilderness advocate who could hike 30+ miles a day.
🛞 Tires
⚙️ Drivetrain
🪢 Recovery
📦 Other
Where to Camp
GPS Coordinates
Import into Gaia GPS, OnX Offroad, or Garmin
Map of Augusta, MT
5-Day Forecast
WHAT YOU'LL NEED
This trail rewards preparation. Run these tools before you load up, the numbers matter.
Tire Size Calculator
Convert tire sizes and compare diameter differences before you swap.
Running 35s or 37s? Confirm fitment and sidewall height before you go.
Gear Ratio Calculator
Find the right gear ratio after lifting or upsizing tires.
Low-range crawl ratio is everything on technical terrain, calculate yours first.
Wheel Fitment Calculator
Calculate backspacing and offset so wider wheels clear your suspension.
Extra wheel width = extra clearance on tight lines. Check offset before buying.
MPG Calculator
Estimate fuel economy after a tire upgrade, important for remote runs.
Bigger tires cut MPG. Plan your fuel stops for this trail.
Trail Matchmaker
Not sure this trail matches your rig's current build? Find out fast.
Answer 6 questions and confirm Bob Marshall Wilderness Access is right for your setup, or find a better match.