The Patterson-Gimlin Footage.

[putnam6]

I have a business associate/friend that I've known for 35+ years. About 10 years ago we were chatting and he told me of an experience he had as a kid. His best friend was a Mormon kid whose family used to go to a retreat in the Utah wilderness every summer and he was invited to go along. He told me that one afternoon/early evening he and his friend decided to go down to a small lake and do some fishing before it got too dark. They were walking down the dirt trail to the lake when suddenly a huge hairy creature stepped out of the brush and onto the trail about 100 feet ahead of them. He said it was at least 8 feet tall and it stopped and turned toward them. They froze - then the creature bounded off the other side of the trail and went up a heavily forested embankment at an unbelievable speed, snapping branches and making an ungodly racket. He turned to his friend only to see that he was already gone running back up the trail! He took off after his friend and they told the parents what happened but of course they didn't believe it.
This guy has zero reason to lie to me, in fact as he was telling me goosebumps literally rose up on his arms. He said it happens every time he thinks about it.

Its stories of encounters like this add to the circumstantial evidence, with the physical evidence of tracks and casts. The chances all of these are hoaxes, lies or misidentifications are astronomically small. 

As for Willow Creek and Patty plenty of sightings are still being reported to this day, if it was a money grab one would think the suit and story would be worth a small fortune