There are four fields of evidence:
1) Testimony
2) Trace evidence
3) Photographic evidence
4) Fossils
The testimony can be broken down further into pre-European and modern (post Columbus). It is the largest collection if evidence, but (as you accurately write and my link to Glickman illustrates) it's the weakest. But it cannot be discounted, especially if/when it can be combined in a particular report with trace and/or photographic evidence.
The trace evidence can be strong evidence, again, especially when combined with other evidence.
Ditto photographic. Remember, the Patterson/Gimlin event combined all three (testimony, trace evidence, and motion picture photography), and pretty much sealed the deal. The fact that Science refused to accept it as *adjective* evidence only strengthens the theory that they are actively discouraging discovery, which is a theory that gains strength with each additional consideration.
The fossil evidence is both too old and only found in Asia thus far, but unlike extraterrestrials, fossils prove that sasquatch type creatures existed in the distant past in Asia.
The problem with testimony today is that The Beast (the media) has found use for sasquatchery and has used it to the detriment of the phenomenon itself. Now everybody is seeing a sasquatch behind every tree. Every noise out there is a sasquatch. Every movement in the brush is a sasquatch. More than damaging sasquatchery, however, this is destroying Science just as surely as it's destroying society and culture.