Cascade is probably one of the best short hikes you can do in the Emerald Bay area. It is only 1.5 miles round trip from the Bayview Campground.
If you like to ride your bike downhill, on great trails, then you want to ride Downieville Downhill. And if you’re going, the best thing to do is get a shuttle ride to the top. Yuba Expeditions offer daily shuttles (book in advance!), and have demo bikes plus all the gear and supplies you’d need.