natrona county

The onset of Prohibition in 1919 not only didn’t stop drinking in Wyoming, it added new layers of lawlessness—bribery, corruption, murder. Enforcement officials had to battle crime in their own ranks, too. One high-profile federal case charged corruption at all levels in Casper, but the jury refused to convict.

After leaving the North Platte River near present-day Mills, Wyo., Oregon Trail travelers journeyed 10 miles or so through windswept, sometimes rocky terrain before coming through a shallow pass, now known as Emigrant Gap. Beyond it, at the base of a hill lay Mineral Lake, an alkali pond.

The Mineral Leasing Act of 1920 established the modern system by which oil and coal companies may lease federal land. This system has proven enormously beneficial to Wyoming’s state coffers since it was first enacted nearly 100 years ago. How this all came about is a story of early oil producers looking for a way around a presidential order and a highly contentious Supreme Court case, all with lucrative results for the state of Wyoming—and a stabilizing result for the industry.