Grass Valley is a city in Nevada County, California, United States. Situated at going on for 2,500 feet (760 m) in height above sea level in the western foothills of the Sierra Nevada mountain range, this northern Gold Country city is 57 miles (92 km) by car from Sacramento, 64 miles (103 km) from Sacramento International Airport, 88 miles (142 km) west of Reno, and 143 miles (230 km) northeast of San Francisco. As of the 2010 United States Census, its population was 12,860.

Grass Valley, which was originally known as Boston Ravine and forward-looking named Centerville, dates from the California Gold Rush, as does easily reached Nevada City. Gold was discovered at Gold Hill in October 1850 and population grew nearly the mine. When a proclaim office was received in 1851, it was renamed Grass Valley the neighboring year for unknown reasons. The town incorporated in 1860.

The vital history of Grass Valley mining belongs to the North Star, Empire and Idaho-Maryland mines, for continuous production on culmination of a span of years. From 1868 until 1900, the Idaho-Maryland mine was the most productive in the district. From 1900 until 1925, the North Star and the Empire produced the most gold in the county. In 1932, the Empire and North Star were physically amalgamated at the 4600-foot level and 5300-foot level.

Grass Valley has the Empire Mine and North Star Mine, two of California’s richest mines. George Starr, manager of the Empire Mine, and William Bowers Bourn II, the owner, donated mine property which became Memorial Park.^: 42 Wiliam Bourn Jr. had taken exceeding management of the Empire Mine in 1878 after his father’s death, replacing water aptitude with steam. In 1884, Bourn purchased and rejuvenated the North Star mine. The Idaho and Maryland mines were consolidated by Samuel P. Dorsey in 1893. In 1925, Errol MacBoyle acquired the Idaho-Maryland. By 1938, the Idaho-Maryland was the second largest gold producer in the country. However, gold mining operations in the Place ended during WWII, due to War Production Board Limitation Order 208. After the war, renewed operations were attempted, but according to Gage McKinney, “…by the mid-1950s mining was no longer profitable in what had been the richest gold mining district in California.”