Summit County Population History, 1970-2010

From 1970 to 1980, Summit County was considered to be the fastest growing county in the country, with a 232% increase in the permanent resident population. The following decade, from 1980 to 1990, the county experienced slower growth, as the increase was 45.6%.

Between 1990 and 2000, the population nearly doubled, growing from 12,881 to 23,548 residents, an increase of 82.8%. This ranked Summit County again as one of the fastest growing counties in Colorado and the country, as it grew almost three times as fast as the state average and eight times faster than the national average.

From 2000 to 2010, as shown in the table below, the county added approximately 4,446 residents, which represents a growth rate of approximately 18.9%, or 1.9% per year. In comparison, annual growth rates from 1990 through 2000 were higher, averaging approximately 7.2% per year. From 2000 to 2006, the State Demographer’s estimates show that the county was again ranked among the top ten fastest growing counties in the state (#8). From 2001 to 2002, the State Demographer’s estimates indicate that the county was ranked as the fastest growing county in the state (in terms of percent change), with the permanent resident population growing 10.1% in one year.

In recent years, the population growth rate in the county has slowed. The State Demographer estimates that the annual rate of change from 2005 to 2010 was 1.1%, which ranks Summit County approximately 23rd among counties in the state in terms of percent growth in population.

Summit County - Permanent Resident Population Growth
Time Frame
% Change
New Residents Added
Estimated Ending Population
1970 - 1980
1980 - 1990
1990 - 2000
2000 - 2010
4,446 27,994

Source: U.S. Census Bureau, State Demographer, and Summit County Planning Department.