Head south on Mountain Home Rd., take the third trail in (about 3/4 to 1 mile down) then follow the map on Yuba Expedition's website. The trailhead is at 4450 ft. and it goes to Bald Mtn at 5600 feet. A nice mixture of single track and fire roads.
www.yubaexpeditions.com gives the best map; 8 miles west of Downieville take the Forest City/Goodyers Bar turn off; right the T, then 9 miles of DIRT road. After the Forest City sign, cross the bridge and park immediately on your right. If you want to get away from it all, this is it. The best kept secret in the Sierra's for cross country riding! If you go in the summer, take lots of water and energy food.
http://www.singletracks.com/item.php?c=1&i=1725