What am I doing you ask? I belong to: Cal4wheel, CORVA, The Blueribbon Coalition, and the Gear Grinders 4 Wheel Drive Club. We as the club have many adopt-a-trails that we maintain in conjunction with the BLM, USFS, and NPS IIRC. We also help The Friends Of Cerro Gordo with manpower and supplies as needed.
I have only been 4 wheeling for a little over 2 years but before that when I rode dirt bikes I worked with the USFS every year for 8 years clearing the trails in the Kern Plateau AKA Kennedy Meadows. I do what I can to help with my back as well as my wallet, just wish I could afford to do more!