Tioga Pass, at 9945 feet, is California's highest automobile pass. The road to the pass was constructed in two parts: the first was a 56-mile wagon road from Crane Flat on the west side to a silver mine on the east slope of the Sierra Nevada, built in 1883 at a cost of $61,000 and ending a short distance east of Tioga Pass; the mine closed the following year because it was not profitable. Construction of the second part, from Lee Vining on the east side to Tioga Pass, began in 1902 and was completed in 1910 at a cost of $63,000. Regarded as a monument to the skill of the state engineers, it was routed up Lee Vining Canyon, had a maximum grade of 7%, and was a narrow road with a steep drop to Lee Vining Creek below. The original wagon road from Tioga Pass to Crane Flat, by then a seldom-used toll road, was purchased in 1915 by National Park Service director Stephen Mather and donated to Yosemite National Park. With that, the Tioga Pass Road was complete, and automobiles began using it in 1915. As automobile traffic increased, so did the need for improvements; because it remained an all-dirt road until 1937, maintenance costs were very high. After extensive study, the road within Yosemite Park was completely rebuilt in 1961 at a cost of $7,000,000, and the Lee Vining grade east of Tioga Pass and outside Yosemite was rebuilt from 1965 to 1970 at a cost of $6,600,000. Today, the Tioga Pass Road is regarded as California's most scenic mountain road and as one of the most beautiful park roads in the National Park system.