Colorado’s population increased by 50% between 1990 and 2010, from 3.3 million to 5.0 million. The blue layer on the map shows population density.

In earlier decades, wells were drilled on the outskirts of Front Range cities. As population grew, many neighborhoods extended into former oil and gas fields. Residential areas now brush up against, or even overlap, former oil and gas fields. This is particularly evident in Greeley. Each orange dot on the map is an abandoned* oil or gas well.

Slide up and down to compare between 1990 (top) and 2010 (bottom).

*Dry or plugged and abandoned as of January 8, 2016 (date of data download). The 1990 view excludes wells drilled after 1990. Some wells do not have a drill date. However, because most of those wells pre-date computerized record-keeping, they are included in both views.

Data sources: Colorado Oil and Gas Conservation Commission, U.S. Census Bureau.