25-30 miles round trip. You'll reach Twin Lakes in about 12 miles. Pass is almost 10,000' elevation. 25-40 miles round trip. Ride up Hwy 120 west from Lee Vining 12 miles to the entrance of Yosemite National Park at Tioga Pass.
Road is narrow and steep, watch for rocks on the road and traffic.
Pay the entrance fee and ride another 7 miles downhill to Tuolumne Meadows, if you don't mind riding back uphill. Below 8000' elevation. 11.3 miles round trip. Below 9000' elevation. 9.1 miles round trip.