Figure 5. Exploration history of central Utah (thrust fault locations modified from Willis, 1999). The map area represents about 276 square townships. The map area has had fewer than 120 wells drilled since 1918, which means one well has been drilled per every two townships or one well per about 72 square miles. The increase in drilling in the 1970s and early 1980s was due to significant increase in oil prices from the Arab oil embargo, the discovery of the Pineview field in northern Utah, and the Iranian revolution.