Mountain biking in Downieville, CA

A heavily padded mountain biker negotiates a trail in the rugged heart of California's gold country. The destination is Downieville, a former timber and mining town about 100 miles northeast of Sacramento that's now a mountain biking hub. Riders are shuttled to a trail head near the top of Sierra Buttes to begin their ride, and it's all downhill from there -- but treacherous in places. Sheer cliffs, aqua-blue lakes, green meadows and waterfalls are attractive, and sometimes distracting, to bikers.