Untitled Sighting

My neighbor is a seasonal wildlife biological technician for Redwood National Park.  He has been working several seasons doing Spotted Owl surveys and is very familiar with local wildlife. One evening just before sunset he and his partner were walking with a cage of six mice that had sat in the same cage without being cleaned for 3 or 4 days and it smelled to high hell. They were several miles south of Bald Hills Road at about 2,000 feet up an approximately 3,000 foot mountain in extremely rugged and isolated terrain several miles from the nearest logging road. After bushwhacking for about thirty minutes heading downhill they stopped in their tracks when they heard a large branch snap.  There are a lot of bears and mountain lions in the area and they are familiar with with stalking cats.  The creature was quick and agile like a cat but sounded heavier than a bear.  It also sounded like it was walking on two legs.  They would hear it behind them and a little later it would be way ahead of them, sometimes on the other side of them They figured it was crossing right behind them and then passing them up on the other side.  By this time it was getting dark in the forest, late twilight, when my friend started looking over his shoulder quite frequently.  It was at this time that he saw a large dark animal dash across their trail on two legs.  He has seen the P-G Film and is familiar with sasquatch and he says that it moved with the same motion, just much quicker. He also noted it seemed a little thinner than Patty.