Despite efforts to develop alternatives, the great majority of visitors arrive by private car. There are no restrictions on driving into the park other than the logistical one that at peak times more cars are trying to enter the park or circulate within it, than can be comfortably accommodated.
Public transportation into Yosemite Valley is provided by YARTS buses and VIA buses. You can also ride an AMTRAK train and buy a ticket which includes a through bus connection. Many private operators provide bus tours, either for day trips or in packages which include lodging.
Free shuttle buses serve the eastern end of the Valley, and you are encouraged to park your car, either in one of the day use parking lots, or in the parking area associated with your accommodations if you are staying over. The buses serve some areas, such as the Happy Isles Nature Center (trailhead for Vernal and Nevada Falls, and Half Dome), the Mirror Lake trail, and the stables, closed to private cars. Free shuttle busses also provide service from the Valley to Glacier Point (in summer), Badger Pass (winter), and Tuolumne Meadows (summer).
RVs and trailers are permitted in the Park. In the Valley, the maximum length for RVs is 40 feet, and for trailers 35 feet. Be aware that the number of camp sites that can accommodate RVs or trailers of that length is limited. Camp sites in the Park do not include hookups.
There is NO gas available in Yosemite Valley. Gas stations are at El Portal (Highway 140), Wawona, Crane Flat and Tuolumne Meadows (when Tioga Pass Road is open).
There are three entrances to Yosemite National Park from the west, which are open all year
The Arch Rock Entrance overlooking the Merced River is on Highway 140 from Mariposa and Merced.
The Big Oak Flat Entrance is on Highway 120 from Manteca. Highway 132 from Coulterville and Modesto comes in to Highway 120 at Smith Station, about eight miles west of the Big Oak Flat Entrance.
The South Entrance is on Highway 41 from Oakhurst and Fresno. This entrance is also convenient for Mariposa county locations on Highway 49 South, which joins Highway 41 at Oakhurst, especially if your destination is Wawona, Badger Pass or Glacier Point.
Also on the west is the Hetch Hetchy Entrance (open all year), on Hetch Hetchy Road which branches off Highway 120 just before the Big Oak Flat Entrance.
From the east, the Tioga Pass Entrance on Highway 120 from Lee Vining and Highway 395, is open late May or early June through October or November, depending on snow conditions.
Because weather conditions can change quickly, it is recommended to carry tire chains from October through April. Depending on actual snow conditions in the Park, chains may be required at any time during this period (you will be turned back at the entrance if you do not have them). You can inquire at the visitor centers in Mariposa (for Highway 140), Coulterville (for Highway 132 / 120), Groveland (for Highway 120), and Oakhurst (for Highway 41) to determine current chain requirements. Chains can be rented or bought at these locations (except Coulterville).
You are somewhat more likely to encounter snow conditions on highways 120 and 41, which both reach 6000’ elevation, but if there is snow in Yosemite Valley, at the 4100’ level, you will need chains regardless which highway you use.