Boulder is the county seat and most populous city of Boulder County and the 11th most populous city in the U.S. state of Colorado. Boulder is located at the base of the foothills of the Rocky Mountains at an elevation of 5,430 feet. The city is 25 miles northwest of Denver. Wikipedia

San Francisco, officially the City and County of San Francisco, is the cultural center and a leading financial hub of the San Francisco Bay Area and Northern California. Wikipedia