You're right Greg, but in the SE slopes, OHV use (ATV's, 4x4's, bikes, etc) contribute to habitat loss and pollution big time.
Responsible use is fine, but people are tearing up the streams, refuelling on the banks, washing oil and mud off in the water, tipping vehicles and dumping gas, basically doing all the things that industry get fined for (well would with more enforcement).
(Also access is easier for poachers, new trails cause sediment point sources, trails affect wildlife movements, etc)
Why can recreational users destroy stuff for their enjoyment when industry using the resource has to minimize their impact. I can tell you, there is a large impact on fisheries from random campers and OHV, rivals industry in my mind!!
Cheers,
Paul