General George Patton's Desert Training Center was one of the largest military installations ever established in the United States — a vast network of camps spread across the California, Nevada, and Arizona desert where American forces learned to fight in extreme terrain. The main headquarters was Camp Young, where Patton's 3rd Armored Division was based. Camp Pilot Knob was one of dozens of satellite camps, a sub-camp of the Desert Training Center in Imperial County.

The location was chosen for its harshness. Five miles northwest of Yuma, two miles west of the Colorado River, two miles north of the Mexican border — the desert here is flat, sun-blasted, and relentless. Just north of the Felicity train station, which brought troops and supplies in, the camp was built with the resources of wartime emergency: shower buildings, latrines, wooden tent frames, water storage tanks, a treatment plant, and fire ranges to the north.

The 85th Infantry Division trained at Camp Pilot Knob from June to August 1943, then shipped to Italy, where it fought in some of the most brutal campaigns of the European theater. Men who had sweated through desert exercises in Sonoran summer heat found themselves climbing the Apennine mountains in Italian winter.

The 6th Infantry Division had a different destination. Its training at Camp Pilot Knob prepared it for the jungle warfare of the New Guinea campaign and the Battle of Luzon in the Philippines — conditions as different from the desert as imaginable, but the discipline and physical conditioning carried over. Also at the camp were the 36th and 44th Reconnaissance Squadrons, and the 54th Evacuation Hospital, which both trained soldiers and prepared to treat their wounds.

The camp closed in June 1944. By that point, the men it had trained were already fighting — in Italy, in the Pacific, in the campaign to end the war. The desert returned quickly to what it had been: flat, hot, empty. The infrastructure — wooden frames, tanks, the temporary buildings of wartime — disappeared or deteriorated over the following years.

A California Historical Landmark marker, number 985, was placed at the site in 1990, erected by the State Department of Parks and Recreation in cooperation with the Bureau of Land Management and the E Clampus Vitus historical society. It reads simply that the camp was here, that it trained troops for World War II. That is most of what remains.

Camp Pilot Knob took its name from the prominent rocky hill south of the camp — Pilot Knob, a landmark visible for miles across the flat desert, used as a navigation reference by travelers on the Southern Emigrant Trail decades before the Army arrived. The hill is still there, unchanged. From the air, the knob is recognizable: a dark volcanic outcropping rising from the surrounding flatness like a navigational waypoint, which is precisely what it has been for nearly two centuries of desert travel.

Near the camp's site is the town of Felicity, California, which was established in 1986 and is designated the Official Center of the World by the Imperial County Board of Supervisors — a designation that gives the desert around Camp Pilot Knob an entirely different kind of fame.