Trail Difficulty Ratings
Chart
Rating:

Graded dirt road. Dry, or less than 3" water crossing depth. Gentle
grades. 2WD under all conditions except snow. No width problems, two
vehicles wide.
Rating: 
Dirt road. Dry, or less than 3" water crossing depth. Some ruts.
Slight grades, up to 10 degrees. 2WD under most conditions. Rain or snow
may make 4WD necessary. Usually one and a half to two vehicles wide.
Rating: 
Dirt road. Rutted, washes, or gulches. Water crossings up to 6"
depth. Passable mud. Grades up to 10 degrees. Small rocks or holes. 4WD
recommended but 2WD possible under good conditions and with adequate
ground clearance and skill. No width problems for any normal vehicle.
Vehicle passing spots frequently available if less than two vehicles
wide.
Rating: 
Rutted and/or rocky road. No shelves but rocks to 9". Water
crossings usually less than hub deep. Passable mud. Grades moderate, up
to 15 degrees. Side hill moderate up to 15 degrees. 4WD under most
conditions. No width problems, vehicle passing spots frequently
available if less than two vehicles wide.
Rating: 
Rutted and/or rocky road. No shelves. Rocks up to 12" and water
crossings up to 12" with possible currents. Passable mud. Moderate
grades to 15 degrees. 6" holes. Side hill to 20 degrees. 4WD
required. No width problems.
Rating: 
Quite rocky or deep ruts. Rocks to 12" and frequent. Water
crossings may exceed hub depth with strong currents. Shelves to 6".
Mud may require checking before proceeding. Moderate grades to 20
degrees. Sidehill may approach 30 degrees. 4WD necessary and second
attempts may be required with stock vehicles. Caution may be required
with wider vehicles.
Rating: 
Rocks frequent and large, 12" and may exceed hub height. Holes
frequent or deep (12"). Shelves to 9". Mud 8" deep and
may be present on uphill sections. Grades to 25 degrees and sidehill to
30 degrees. Water crossings to 18" and may have strong currents.
1-1/2 vehicles wide. 4WD required. Driver experience helpful.
Rating: 
Heavy rock and/or severe ruts. Rocks exceeding hub height frequent.
Shelves to 12". Deep mud or uphill mud sections. Steep grades to 25
degrees and can be loose or rocky. Water crossings may exceed 30"
in depth. Side hill to 30 degrees. One vehicle wide. Body damage
possible. Experience needed. Vehicle Modifications helpful.
Rating: 
Severe rock over 15". Frequent deep holes over 15". Shelves
over 15". Mud bog conditions (long, deep, no form bottom). Over
30" water crossings with strong currents. Steep grades over 30
degrees. Sidehill over 30 degrees. May not be passable by stock
vehicles. Experience essential. Body damage, mechanical breakdown,
rollover probable. Extreme caution required.
Rating: 
Severe conditions. Extreme caution recommended. Impassable by stock
vehicles. Winching required. Trail building necessary. May be
impassable. Impassable under anything but ideal conditions. Vehicle
damage probable. Personal injury possible. Extreme caution necessary.