The Yosemite Riverside Inn is 11 miles (18 km) outside Yosemite's northwest (Highway 120) entrance, on Cherry Lake Road half a mile off the highway. The Cherry Lake Road turnoff is just over 10 miles west of Yosemite, and just under 3 miles (5 km) east of Buck Meadows. The turnoff is well signed; you'll find it just east of a bridge over the Tuolumne River (the turnoff west of the bridge takes you to Rainbow Pool, a popular swimming hole).
Though Google's map makes things look a bit squiggly and confusing (and labels the Cherry Lake Road as Forest Route 1N07 instead, to boot), the inn is easy to find. Just take Cherry Lake Road, and in about half a mile, you'll find the sign heralding the turnoff to the inn's driveway.