The pilot received a phone call around 1900 that his sister had been admitted to the hospital with a medical condition. The pilot decided that he would fly from his location, Klamath Falls, Oregon, to where his sister was in Eugene, Oregon. The pilot performed a preflight inspection but failed to fuel the airplane. He took off from Klamath Falls at 2100. Shortly after reaching his cruising altitude of 12,500 feet he realized that he had not fueled the airplane and upon checking the fuel gauges determined that the fuel tanks were empty. He radioed Eugene airport tower that he was out of gas and anticipating a forced landing in the mountains. The engine stopped and he turned the airplane to the southeast to try to make a small Forest Service runway at Tokettee. He could see the ground and mountainous terrain getting closer, he determined that he would not make it, and proceeded to force land the airplane on a steep snow covered slope. The pilot had survival equipment onboard that included blankets, food, satellite phone, flares, and a handheld VHF radio. He had hurt his leg and ribs during the landing, but was able to exit the airplane, set up a shelter, and sporadically contact his wife with the satellite phone. The Civil Air Patrol spotted the pilot's flare marker around 0330, and a National Guard helicopter affected the rescue about 0805.