Population Timeline for Boulder, CO with establishment of surrounding areas.

1858 (Oct. 17) - Original camp of gold-seeking men of European descent camped at the Red Rocks, above the entrance of Boulder Canyon.  Population of 12 men in this first encampment.

1859 - (Jan. 15) Mining District 1, also called Gold Hill Mining District, is established

1859 - Washington Lode was established for it's "wagon coal mine" where settlers would drive up their wagons and load up with coal to take to their home or business for heating and cooking.  This was later sold to Joseph Marshall and the encampment town of Marshall was named for him.  The coal and iron town became knows as one of the toughest and fight-ingest in the entire west.

1859 (Feb. 10th) - Due to a snow storm in the mountains, there were 56 men who came out of the mountains to establish a supply town.  These 56 shareholders (all miners from Gold Hill) establish Boulder City with 4,044 lots surveyed and offered for sale at $1,000 per lot.

1860 - Ward Mining District is established

1860 U.S. Census - Nebraska Territory (included the following communities: Boulder City, Altoona City, Boulder Creek Settlement, Gold Hill Settlement, Miravalle City, Platte River Settlement)  Population of Boulder was 324 residents.

1861 - town of Altona (mouth of Left Hand Canyon) is incorporated (first called Modoc, then Ni Wot, then Altona)

1861 - where the Overland Stage Stop is located, at the St. Vrain River, the town of Burlington is established (Today, the Overland Stage Route is Highway 287 which runs through Longmont, CO)

1861 - Colorado becomes a recognized Territory, combining portions of Utah, Nebraska and Kansas Territories.

1865 - town of Valmont (Valley+Mountain) is platted

1869 - community of Ryssby is established by seven Swedish families (along what is 63rd Street today)

1870 U.S. Census - Boulder County population was 1,939 of those 343 lived in Boulder City with Carson and Frannie Arbuthnot being listed as the oldest residents in Boulder City.

1871 - town of Longmont (for Long's Peak) was founded by the Chicago-Colorado Colony.  The town of Burlington relocates a quarter-mile north to join up with Longmont.

1874 - Even before Colorado had become it's own territory, organizing and lobbying for the university had began in 1860.  In 1874, Boulder was awarded the designation for the University of Colorado after the town of Boulder had raised $15,000 and acquired 44.9 in donated acres, beating out communities such as Pueblo, Colorado Springs, and Denver.  Since there are not enough qualified students to attend the university, the State Preparatory School - a high school, is started to prepare the students to enter the University.  This is now Boulder High School and still is represented by the original colors - purple and gold - and the original mascot - the Panthers.

1875 - town of Ni Wot (now Niwot) is established by the railroad company.  Land was donated by Porter T. Hinman, originally a gold miner, for the establishment of this community.

1880 U.S. Census - Boulder - population 3,069 

1882 - town of Louisville is incorporated.  The town first began as the Welch Mine in 1877, a coal mine that served Denver.  The town was established to serve the coal company by Louis Nawatny who platted his property and named the town for himself.

1889 - town of Broomfield established, not incorporated until 1961.  Broomfield is was an agricultural community where grains were grown and loaded on the train to transport to Zang's Brewery.

1890 U.S. Census - Boulder - population 3,330 

1890 - town of Lafayette is incorporated.  In 1888, 150 acres was platted to be the town of Lafayette to serve the growing coal mine.  Platted by the widow, Mary Miller, on her farm which had been established by her and her husband, Lafayette Miller, in 1871.

1896 - town of Superior is founded and later incorporated in 1904

1900 U.S. Census - Boulder - 6,150
1910 U.S. Census - Boulder - 9,539
1920 U.S. Census - Boulder - 11,066
1930 U.S. Census - Boulder - 11,223
1940 U.S. Census - Boulder - 12,958
1950 U.S. Census - Boulder - 19,999
1960 U.S. Census - Boulder - 37,718

1970 U.S. Census - Boulder - 66,870
University of Colorado students were counted by the U.S. Census in Boulder (rather than their home town) for the first time in 1970.

1980 U.S. Census - Boulder - 76,685
1990 U.S. Census - Boulder - 83,312
2000 U.S. Census - Boulder - 94,673
2010 U.S. Census - Boulder - 103,600 (estimated)