 Denver is located 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 . 
