| Boulder County Colorado Cities/Towns - Allenspark, Boulder (County Seat), Coal Creek, Eldora, Eldorado Springs, Erie, Gold Hill, Gunbarrel, Jamestown, Lafayette, Longmont, Louisville, Lyons, Nederland, Niwot, Superior, Ward |
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Your Ad Here Boulder County is the sixth most populous of the 64 counties of the State of Colorado of the United States. The United States Census Bureau estimates that the county population was 282,304 in 2006. The county seat is the City of Boulder. History Boulder County was one of the original 17 counties created by the Territory of Colorado on 1861-11-01. The county was named for Boulder City and Boulder Creek, so named because of the abundance of boulders in the area. ![]() |