Basic Earth Science Systems, Inc. was founded in 1969 and is based in Denver, Colorado.Basic Earth Science Systems, Inc. engages in the exploration, acquisition, development, operation, production, and sale of crude oil and natural gas in the United States. Basic Earth Science Systems, Inc. focuses its activities in the North Dakota and Montana portions of the Williston basin, the Denver-Julesburg basin of Colorado, the southern portions of Texas, and the onshore portions of the Gulf Coast. As of March 31, 2009, Basic Earth Science Systems, Inc. owned working interest in 94 producing oil wells and 36 producing gas wells in the states of North Dakota, Montana, Colorado, Texas, and Wyoming. Basic Earth Science Systems, Inc. estimated proved developed and undeveloped oil and gas reserves were 794,000 barrels of oil equivalent.