But if 100 miles sounds a wee bit daunting, the LA River Ride, which turns 10 in 2010, offers shorter jaunts, too. Like a 70-miler. And a Half Century, which is 50 miles (no surprise). There's also a 36-mile training ride, and a 15-mile course for families and younger cyclists.
Of course, the routes don't stick strictly to the river -- everything begins and ends at the Autry National Center in Griffith Park, and there are a few zigzags and offshoots, like through downtown.
That said, the LA River Ride is a fine way to be close to a channel most Angelenos spend far too little time getting to know. And when you're not out riding and river-admiring, you'll be listening to music and eating at an international food faire.
The Los Angeles County Bike Coalition is behind the annual ride. Money raised from the day will help fund a bicycle pathway that stretches from Long Beach to the Valley. Talk about epic.