The northern coal fields operated between 1859 and roughly the early 1960s. These early mining operations were one of the primary drivers of Latino immigration to Boulder County at the end of the 19th and beginning of the 20th century.
At one time, there were more than 100 coal mines spanning the region, from the southern edge of Boulder near Marshall Road east to Superior, Louisville, Lafayette, Erie, Frederick, Firestone and Dacono.
A search of the Western History and Genealogy section of the Denver Public Library revealed the names of the following coal mines in Boulder and western Weld Counties.
Coal mines in Boulder County
Acme
Archer
Big Lake
Black Diamond
Boulder
Boulder Valley
Caledonia
Cannon
Capitol
Centennial
Columbia
Cracker Jack
Fox
Gladstone
Globe
Gorham
Hecla
Hi-way
Industrial
Jewell
Leader
Marshall
Marshall No. 2
Marshall No. 3
McGregor
Mitchell
Monarch No. 1
Monarch No. 2
Montgomery
New Baker
New Centennial
New Morrison
Nonpareil
Paramount
Parkdale
Pittsburg
Pluto No. 1
Pluto No. 2
Red Ash
Regal
Rex No. 1
Rex No. 2
Simpson
Standard
State
Stewart
Sunnyside
Vulcan
Boulder County mines that may have mined coal or other minerals, such as gold
B&M
California
Cardiff
Crown
Eclipse
Glendale
Hartman
Ingram
Logan
Matchless
Summit
White Crow
Coal mines in Weld County
Baum
Clayton
Columbine
Eagle
Eureka
Evans
Farmers
Firestone
Galeton
Golden ash
Graden
Grant
Imperial
Morrison
Puritan
Russell
Shamrock
Sterling
Washington
Wellington
Witherbee
