Since the 1940s Los Angeles has diverted water from this lake, exposing striking towers of tufa, or calcium carbonate. Court victories by environmentalists have meant fewer diversions, and the lake is rising again. Although to see the lake from U.S. 395 is stunning, make time to walk about South Tufa, whose parking lot is 5 miles east of U.S. 395 off Highway 120. There in summer you can join the naturalist-guided South Tufa Walk, which lasts about 1½ hours. The sensational Scenic Area Visitor Center, off U.S. 395, is open daily (8–5) from mid-May through mid-October; hours vary at other times, and it's closed in winter. The center's hilltop and sweeping views of Mono Lake, along with its interactive exhibits inside, make this one of California's best visitor centers. Rangers and naturalists lead walking tours of the tufa daily in summer and on weekends (sometimes on cross-country skis) in winter. In town at U.S. 395 and 3rd Street, the Mono Lake Committee Information Center & Bookstore, open 9 to 5 daily, has more information about this beautiful area.