I know nothing about the DB National Forest, but generally speaking, most of the National Forests have very specific regulations regarding off-road vehicle uses nowadays,...and that information should be readily available to you by contacting the Forest Service office that administers that NF. I'm not sure if it is country-wide, but the National Forests in this area have free "travel maps" available that show you where you can legally go,...and what types of vehicles you can use to get there.
One of the "pet peeves" of many of us that hunt National Forests is dealing with the regular violators of Forest Service rules/regulations regarding motorized-vehicle use and off-road regulations. Moral of this story: If you are going to recreate on National Forests (or other public lands), contact the agency in charge and find out exactly what you can legally do in terms of vehicle use. (As an incentive to staying legal, I can tell you the NF that I regularly hunt has a fine of up to $5,000 and up to a year in jail for violating off-road regulations,...hence, it's a good idea to know what you can do or not do...
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