Utah's famed measured mile at the Bonneville Salt Flats lies about seven miles beyond this point, with the course at an elevation of about 4,218 feet above sea level. The total course that includes the measured mile varies from year to year, but in recent runs it has been laid out as a path 80 feet wide and about ten miles long, marked by a black reference stripe down the middle, and the curvature of the earth makes it impossible to see from one end to the other. World land-speed record runs there are timed under the jurisdiction of the United States Automobile Club as an electronically timed average of two runs over the measured mile within one hour, one in each direction. The first world land-speed record on the Bonneville Salt Flats was set on September 3, 1935, by Sir Malcolm Campbell at 301.13 miles per hour. Craig Breedlove became the first man to exceed 400, 500, and 600 miles per hour, and his 600.601-mile-per-hour record, set on November 15, 1965, was broken on October 23, 1970, by Gary Gabelich, whose new record was 622.407 miles per hour. Gabelich's rocket engine Blue Flame and Breedlove's jet-powered Spirit of America both used specially designed inflatable tires pre-tested to speeds above 800 miles per hour.