Exell, on the Moore-Potter county line just off U.S. Highway 287 in south central Moore County, derives its name from an inversion of the LX (see LX RANCH) cattle brand of the pioneer rancher Lee Bivins. It grew simultaneously with the Exell Helium Plant, which was built to produce helium for use as a lifting gas in semirigid and nonrigid airships and in observation and barrage balloons during World War II. As the town's sole industry, the plant began production in March 1943, only ten months after construction started. It was soon operating at 25 percent above its rated capacity. Railroad service was provided by the North Plains and Santa Fe Railroad, which furnished specially made cars to pick up the large cylindrical tanks of compressed helium for shipment. During construction housing was built for more than 1,000 plant employees. Through the mid-1980s the Exell plant was a leading producer of helium. With improved highways and transportation, however, the resident populace decreased. Mail for the plant's personnel comes through the post office at Masterson.