An article about the bike trail, at YubaNet, from a recent visitor from Nevada City (who also received our input) and it is a very nice perspective.
“Jan. 13, 2010 - During the winter months, when snow and mud cover local bicycle trails in the foothills, a 32-mile long bike trail in Sacramento County offers a paved sinuous path through the heart of the American River Parkway.
“Known as the Jedediah Smith Memorial Bicycle Trail, the path flows from Folsom Lake at Beal's Point State Park and ends at Discovery Park just outside downtown Sacramento where the Sacramento and American rivers converge.
“Begun in the 1950's as a way to protect a slice of open space from development, the parkway is a natural unbroken corridor managed mostly by the Sacramento County parks department and kept tidy by area non-profit groups and volunteers.
“Though surrounded by busy city and suburban life, the 5,000-acre interior of the parkway offers an outdoor sanctuary for people, wildlife and native plants.
“You really feel like you're in the middle of nowhere. You can get away, where you can't hear sounds, of traffic, or anything," said Annie Parker, spokesperson for Sacramento County parks department.
“Each year, five million people come to picnic, ride horses or bicycles, hike, walk the dog, bird watch and enjoy native flora.
"We get more visitors than Yosemite," said David H. Lukenbill, founder of the American River Parkway Preservation Society.
“To Nevada County residents with a different perception of what wild is, the parkway isn't exactly solitude and chances are slim that you will encounter a bear or mountain lion during your visit. Look for egrets and hawks, Blue and Live Oak, mining and Native American history and soon spring wildflowers. For those who struggle with steep foothill bicycle climbs, the Jedediah Smith trail is relatively level spotted with a few manageable hills.
"It's a gorgeous ride that borders the river the entire time," said Dianna Poggetto, executive director of the American River Parkway Foundation.
"It's full of different nooks and crannies for everybody."