McCamey was the location of a Humble Oil Company Refinery, one of the first built in West Texas. Humble Oil & Refining Company was a corporate predecessor of Exxon Company. An early experiment by Shell Oil Company in massive oil storage in McCamey proved a failure; local oilmen built a reservoir to hold up to one million barrels of oil in an earthen tank, but the limestone formation underneath the tank cracked under the weight of the crude, allowing much of it to leak into the subsurface.