MTBR'S in Ca.
There is yet more legislation coming down from "the hill" locking up what is left of your trails. There are many stories being written now and posted on the www. here are a few links.

US dept of Interiror and BLM study area designation with bill numbers

There are more but you get the point. Bottom line is this. The should, and can be mutual understanding between the "green movement" and off road user's, regarless of the vehicle or animal used for recreation.