The American River Bike Trail is a multi-use, paved path that begins at Mile 0 in Discovery Park (with an extension from the entrance of Discovery Park to the Railroad Museum in Old Sac) and ends at Mile 32 at Folsom Lake. Its official name is the Jedediah Smith Memorial Trail. Since it is a multi-use trail, you will see walkers, runners, cyclists, families, horses, strollers, and the occasional dog. There are several spots along the trail to either park to start your activities, or stop to rest.
One benefit of the parkways East/West direction is that the entire parkway is paralleled by light rail, Hwy 50 and Folsom Blvd. The benefit to this is that you can take the light rail anywhere from downtown Sacramento to Folsom ( around 30+ miles ) and from any exit you will be within a few short miles of the bike trail and river .
Sacramento Valley Cycling has a map online at http://www.saccycle.com/bikewaymaps/map6.htm
The Golden Empire Council has a patch for Boy Scouts who hike or bike the trail.
The Wikipedia entry has many facts about the trail, but very little about how it's used or how it could be used. Feel free to edit this page to add more information, or to add a comment about your experiences on the trail.