I have to agree with C-Fish, these things are the scourge of the backcountry. I have had 2 close calls with these on back roads in the past couple years (only traffic related close call we have ever had) - in both cases they were driving WAY too fast. In SW CO I had a guy (and his family, of course the kids were wearing helmets, but not daddy) come around a corner, doing 45+ MPH, swerve to avoid us and drove right through a meadow at full throttle and kept on trucking. On Hurrah pass we had some guy come up behind us, super fast, then get impatient as we were crawling down some ledges and try and go around us over a bigger drop off. He tipped over, all his beer spilled all over the place. We smiled, waved and kept on going.