On June 28, the US Forest Service released guidance to its field offices entitled "Forest Service Makes it Easier for Visitors to Enjoy National Forests and Grasslands". Even though it doesn't get into details, I believe it offers Forest Service managers at the district level latitude to authorize 4WD access (among a large variety of activities) to previously unauthorized areas (such as forest routes, including rock crawling trails, not on an MVUM) that previously would have required a Special Use Permit (usually a very time consuming process, frequently denied at the end due to some technicality). Though this guidance is largely directed at group activities conducted by outfitters and guides, it specifically includes families, friends and individuals. The guidance that I believe specifically related to the waiver to a Special Use Permit is the following (extracted from the original document that was too large to include as an attachment to this posting):

"Encouraging managers to take greater advantage of allowable waivers when a special use permit is not required, for example, where a proposed use would have only nominal impact on lands, resources, and programs or operations."

I have already sent a message to local (New Mexico) Forest Service management requesting an affirmation that, under this guidance, they would have the latitude to authorize rock crawling access to areas that, in their judgement, would suffer low or no impact from our use of these trails. Trails over what could include rock beds with little vegetation, rocky arroyos (canyons) that are regularly scrubbed of any sign of passage by the next flash flood (5-10 times per year), and any other place in the forest which would suffer low or no impact but for which they would wish to control the number of visitors and monitor impact.

As the document itself is too large to include as an attachment and forum rules prohibit links in open postings, I would encourage anyone interested in pursuing this with their local forest service management to send me a PM and I'll be sure to send a response with a link to the document that will allow you to download it for your use (and forwarding, along with your suggestions, to the forest service folks you deal with).