The pilot had been maneuvering at low altitude below the rim of a canyon in a remote mountainous area and reported that he had done this aerial survey operation in this same canyon several times before. During climb-out from the canyon the airplane failed to achieve enough climb performance to clear the ridge and the airplane impacted terrain at about 8,500 feet mean sea level. The impact resulted in substantial damage to the airplane including the complete separation of the left wing and partial separation of the right wing. The airplane came to rest upright and there was a significant fuel spill, but no postimpact fire. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot also reported that in the future he should maintain a higher altitude for flight over the canyon.