The USGS Central Region Energy Team assesses oil and gas resources of the United States. The onshore and State water areas of the United States comprise 71 provinces. Within these provinces, Total Petroleum Systems are defined and Assessment Units are defined and assessed. Each of these provinces is defined geologically, and most province boundaries are defined by major geologic changes. The Denver Basin Province is located in eastern Colorado, western Nebraska, southern South Dakota, and eastern Wyoming encompassing all or parts of Pueblo, El Paso, Crowley, Lincoln, Kit Carson, Elbert, Teller, Douglas, Jefferson, Denver, Arapahoe, Adams, Washington, Yuma, Morgan, Weld, Broomfield, Boulder, Larimer, Logan, Sedwick, Freemont, and Phillips [...]