Yosemite's western approach follows the Merced River as it falls out of the Sierra Nevada, and this gate is where the foothills end and the granite begins. For about an hour from Mariposa, Highway 140 climbs through a canyon of oak and pine, with the river rushing white and green beside the road, until the walls tighten and you pass through the Arch Rock entrance, where a huge boulder leans over the pavement as if it were a doorway. Beyond it the Valley opens, and the first sight of El Capitan and the Half Dome is one of the great moments of any American road trip.
The history of the place is as much about people as about stone. The Ahwahneechee lived in the valley for centuries, and gold miners poured into the foothills in 1849, soon followed by tourists. In 1864 President Lincoln signed an act that gave the valley to California as a public trust, a precursor of the national parks, and John Muir, the naturalist who walked here in the 1860s and 1870s, argued passionately for its protection. The photographs of Ansel Adams carried the image of the valley across the world.
For a rider, the road is a pleasure, with a narrow, twisting surface that follows the river through shade and sun, with plenty of corners but also heavy traffic in summer, including large recreational vehicles and slow tour buses. Rockfalls and construction have closed parts of the road at times, so check the park website before you go, and note that reservations or entry permits may be required in busy seasons. Mornings are best, before the heat and the crowds build up. Tioga Pass, on the east side, closes with snow from late autumn to late spring.
Fuel is not available at the gate, and the valley floor has only limited services, so fill the tank in Mariposa, about thirty kilometres from the entrance. Pack water, as the sun is strong and the air dry. Spring brings the waterfalls at their fullest, usually from April to June, while autumn brings quiet roads and golden light.