State park several public parks previously or currently maintained at the state level pre-date it. Indian Springs State Park has been operated continuously by the state of Georgia as a public park since 1825, although it did not gain the title "State Park" until 1931. In 1864 Yosemite Valley and Mariposa Grove were ceded by the federal government to California until Yosemite National Park was proclaimed in 1890. In 1878 Wisconsin set aside a vast swath of its northern forests as "The State Park" but, needing money, sold most of it to lumber companies within 20 years. The first state park with
Yosemite National Park Starting 20 million years ago (in the Cenozoic) and lasting until 5 million years ago, a now-extinct extension of Cascade Range volcanoes erupted, bringing large amounts of igneous material in the area. These igneous deposits blanketed the region north of the Yosemite region. Volcanic activity persisted past 5 million years BP east of the current park borders in the Mono Lake and Long Valley areas. Starting 10 million years ago, vertical movement along the Sierra fault started to uplift the Sierra Nevada. Subsequent tilting of the Sierra block and the resulting accelerated uplift of the Sierra Nevada increased the gradient