On May 28, 2007, about 1057 mountain standard time, a Gadbois experimental Apex Cross-5, N751EW, experienced a total loss of engine power and collided with scrub trees near Show Low Regional Airport, Show Low, Arizona. The registered owner was operating the airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, was not injured; the airplane sustained substantial damage. The cross-country flight departed Holbrook Municipal Airport, Holbrook, Arizona, at an unknown time, with a planned destination of Show Low. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot stated to an FAA inspector that the airplane had completed the flight earlier in the day from Show Low to Holbrook, and had required about 3 1/2 gallons of fuel. He took a spare tank of fuel with him on the flight, which he used to top off his main tank when he arrived at Holbrook. On the return flight, he observed that fuel was depleting at higher than normal rate, but believed he could still make it to his destination. He eventually ran out of fuel 1 1/2 miles northeast of Show Low airport. He stated that he believed he had a fuel leak.