The potential for future discovery of oil in the Modoc Plateau and Cascade Range area of northeastern California is dim. If marine strata are present anywhere in the area (except the minor Cretaceous rocks at the west edge), they are buried at undetermined depths beneath Tertiary and Quaternary pyroclastic and flow rocks and freshwater-lake beds. Neither surface geology, gravity surveys, nor the few scattered drillholes appear to encourage hope for oil production, or even for the presence of oil-bearing strata, in the area.

Cretaceous marine sandstones of the Chico and Hornbrook Formations extend at least a few miles beneath the volcanic cover at the west edge of the Modoc-Cascade area, but have proved to be barren of oil and gas to date. Although marine Cretaceous rocks are exposed in central Oregon, none were found by drilling as deep as 12,000 ft (3,658 m) in volcanic rocks a few miles north of the northeastern boundary of this area.