This field trip guide was part of the October 2002 Earth Science Week. PDF download. FT-02-01D
From the Introduction:
Jefferson County has a long history of mineral production, from the early coal mines that helped fuel steam locomotives and the gold mills up in Clear Creek and Gilpin Counties, to the modern crushed stone aggregate quarries that provide much of the raw material for the immense growth in the Front Range region today. High-quality clays along the base of the Front Range have been mined for years to make bricks and ceramics. One of the largest single uranium deposits in the U.S. is located only seven miles from Golden and has been mined up until last year. Gold, derived from the erosion of the large lode deposits to the west, has been mined from the gravels along Clear Creek, sometimes as a byproduct of gravel pits. Even a small oil field once produced crude oil in Jefferson County. Although overshadowed by larger industries such as construction, defense, beer-making, and others, the economic mineral resources of Jefferson County have been an important part of the development of Colorado.