The City of Norman (City) (plaintiff) issued an ordinance annexing tracts of land and permitting only certain uses on those tracts. Oil and gas drilling was not one of the permitted uses. Olive Clouser (defendant) owned 10 acres on one of the tracts. The Clouser family members were the only residents on the entire 10 acres. Diversified Oil Investments, Inc. (Diversified) (defendant) signed an oil and gas lease with Clouser and began drilling operations on the 10-acre property. The City filed for an injunction against Diversified, attempting to stop Diversified from drilling. The defendants argued that the City’s ordinance was invalid. The trial court granted the City an injunction. The defendants appealed.