Mutant Exodus

Geography

The city of Boulder is in Boulder Valley where the Rocky Mountains meet the Great Plains. West of the city are slabs of sedimentary stone tilted up on the foothills, known as the Flatirons. The Flatirons are a widely recognized symbol of Boulder.

The primary water flow through the city is Boulder Creek. The creek was named well ahead of the city's founding, for all of the large granite boulders that have cascaded into the creek over the eons. It is from Boulder Creek that Boulder city is believed to have taken its name. Boulder Creek has significant water flow, derived primarily from snow melt and minor springs west of the city. The creek is a tributary of the South Platte River.

Boulder lies in a wide basin beneath Flagstaff Mountain just a few miles east of the continental divide and about 25 miles (40 km) northwest of Denver. Arapahoe Glacier provides water for the city, along with Boulder Creek, which flows through the center of the city.