The Colorado Territory was created on February 28, 1861, Arapahoe County was formed on November 1, 1861, and Denver City was incorporated on November 7, 1861. Denver City served as the Arapahoe County Seat from 1861 until consolidation in 1902. In 1867, Denver City became the territorial capital. With its newfound importance, Denver City shortened its name to Denver. On August 1, 1876, Colorado was admitted to the Union.
Denver is in the center of the Front Range Urban Corridor, between the Rocky Mountains to the west and the High Plains to the east. Denver's topography consists of plains in the city center with hilly areas to the north, west and south. According to the United States Census Bureau the city has a total area of 155 square miles (401 km2), of which 153 square miles (396 km2) is land and 1.6 square miles (4.1 km2) (1.1%) is water. The City and County of Denver is surrounded by only three other counties: Adams County to the north and east, Arapahoe County to the south and east, and Jefferson County to the west.