I am Trail Ambassador for 3 parks in CT and we have regular trail maintenance days each month and guess what, 95% of the helpers are Mountain Bikers, not hikers, not dog walkers, not trail runners....you get my drift, partially maybe the fact that Mountain Biking is the usually the first group to get banned so some of us feel very motivated to be part of the solution and not the problem....at least in the parks that I am involved in mountain bikers are now seen in a much better light than prior to our involvement.
So I urge all mountain bikers to get involved and the first step is taking the Trail Ambassador course by CTNEMBA, then take the trail building school course, then get a relationship established with the land manager at the park you frequently ride and show them how important mountain bikers and aid in promoting sustainable trail systems.