History of Summit County

Summit County was established in 1861 as one of the Colorado Territory’s original 17 counties. The county border then stretched from the Continental Divide to the Utah line, and from Fremont and Hoosier Passes to the Wyoming line. Six counties were later created from this early Summit County expanse: Grand, Routt, Eagle, Garfield, Moffat and Rio Blanco. Today, Summit County is bounded by the neighboring counties of Clear Creek, Grand, Park, Lake and Eagle.

Gold Rush Days

Summit County first received worldwide attention in 1859 when prospectors discovered gold and silver in the surrounding hills. High country trappers, from 1810-1840, attempted to keep the glittering gold and silver-seamed mountains a secret, but the news filtered out of the remote area to the rest of the United States.

By the summer of 1859, hordes of gold-hungry adventurers scaled the snow-covered Continental Divide to the mineral-rich valley of the Blue River, catapulting this gentle valley from tranquil isolation into the gold rush days. Mine camps lined the Blue River and its tributaries and a parade of colorful characters and scoundrels, like Pug Ryan and Methodist preacher John Lewis Dyer, marched their way on to the pages of history.

Mining Towns & Ski Resorts

Bustling new towns exploded into existence just as quickly as they lapsed into ghost towns, like Parkville, the first county seat. Others, like Breckenridge, Frisco and Dillon, flourished during the days of mining prosperity and clung to life years after the mines played out.

Snow first became became business in Summit County in 1946, when Arapahoe Basin Ski Area opened. With the opening of Breckenridge Ski area in 1961, Keystone in 1970, and Copper Mountain in 1972, “The Summit” became one of the greatest destination ski areas in the nation and was coined “Colorado’s Playground.”

Fast Facts

Summit County Area

396,000 acres
(about 619 square miles)

Annual Precipitation

Approx. 250” snow

Total Number of Housing Units


Average Temperatures

Summer: 68°
Winter: 30°



Sales Tax

State: 2.9%
County: 2%
Breckenridge and Dillon - 2.5%;
Frisco and Silverthorne - 2%
* 2010 Census data