The commercial pilot related that he was attempting to land at a rough and uneven remote airstrip, which was surrounded by mountainous terrain. He added that the southerly approach to the airstrip required a correction for variable, easterly winds between 5 and 10 knots. He said that just before touchdown he elected to add engine power to avoid an area of rough terrain on the northern end of the site. The airplane ballooned, and landed about mid-length along the 1,500 foot-long, by 30 feet-wide airstrip. After touchdown, the pilot realized that he would be unable to stop the airplane before reaching the end of the airstrip, and he added full engine power to abort the landing, but the airplane failed to become airborne again. The airplane continued off the south end of the site, down an embankment, and into a creek bed. The airplane sustained structural damage to the wings, fuselage, and empennage. The pilot noted that there were no preaccident mechanical anomalies with the airplane.