There is enough believable evidence (pre-20th century sightings, stories from native histories, footprints discovered by accident) to suggest that there was/is something undiscovered out there...as a zoologist and hobbyist cryptozoologist, I have an open mind, but without some very solid evidence, I am yet to be convinced of what. I also believe that Ogopogo sightings are often sightings of some real animal...perhaps a really big sturgeon. As a scientist, I am going to look for the most probable explanation first.
Curiously, the BC wildlife act provides protection (or at least it used to) for any unknown species residing in Lake Okanagan, but not for any undiscovered, large primate living in BC.