On Sept. 4, 1964, 28-year-old Donald Shrum and some of his friends went bow hunting in the high Sierras near Cisco Grove in northern California. Shrum was an avid hunter and was familiar with the outdoors.

But during the afternoon, Shrum somehow got separated from the rest of the group. It was starting to get dark so he decided to sleep the night away in a tree for safety. As he tried to get some sleep, Shrum saw a weird white light that zig-zagged through the nearby trees at a low altitude, according to a Web site.

At first, Shrum thought it was a helicopter so he jumped down from the safety of the tree. He lit some signal flares to attract attention to himself. He thought that his friends had launched a rescue party in order to find him. He would soon regret lighting those signal flares.

The strange white light turned in his direction and came to a stop some 50 yards from his tree. Shrum realized that it was no helicopter. It was a weird-looking object unlike anything he had seen before. He quickly climbed back up the tree for safety.

After a little white, Shrum was startled to see three beings approaching his tree. Two of them seemed to be a humanoid-type being, while the third was more like a robot. The three weird beings began to shake the tree in an attempt to dislodge the frightened Shrum. He would later recall a white vapor that shot out from the robot's mouth. The strange vapor rendered him temporarily unconscious, according to the Web site.

When Shrum came to, he felt nauseous. But he was alert enough to throw some lighted matches toward the three beings, who were still trying to get him out of the tree. The lighted matches caused them to back away from the tree momentarily.

Their assault continued. Finally, Shrum managed to load an arrow in his bow and shoot it at the aliens. The arrow hit the robot. It caused a spark to fly, which indicated that the arrow had hit a metallic surface. Shrum managed to shoot two more arrows at the beings, each time causing to them to scatter.

However, a second robot joined the group. Shrum was again rendered unconscious by the strange, white vapor coming from the being's mouth. When he awoke again, the two humanoid beings were now climbing the tree and they were coming after Shrum. He managed to thwart their attack by throwing objects at them and shaking the tree as hard as he could.

The alien attack continued for much of the night. At one point, the aliens created a large volume of smoke that caused Shrum to black out completely.

When he awoke, the young man was barely hanging from the tree by his belt. The aliens were finally gone. Shrum was soon rescued by a search party and reunited with his friends. One of them was able to corroborate part of Shrum's story by stating that he too had seen the UFO. But only Shrum reported the frightening all-night attack by the aliens and their robots. His wife saw him immediately after the incident and stated that her husband was badly traumatized and covered with scratches.

For many years after the incident, Shrum experienced terrible nightmares and suffered from what we now call post-traumatic stress syndrome. He never went bow hunting again. Several times, he would hear an unusual "buzzing" in his ear. The frightened man would believe that they were after him again.