Most people who have seriously studied the evidence agree that we have a lage bi-pedal primate living in the wilds of America. I also agree. What I don't agree with is the assumption that Bigfoots are of the ape family. Here's why.
I've heard vocalization recordings from around the country. One sound in particular caught my attention. The so-called "woop" sound. It is repeated several times and sounds exactly like the vocalizations of a black lemur. Lemurs are primates. Here's another interesting clue or two.
In certain parts of Wisconsin the predominant Bigfoot report describes a "dog-like" or protruding face. Some reports even include a tail. These are lemur characteristics. It may be that we have giant lemurs instead of apes. It might be interesting to study the lemur fossil record and see where that leads.
We know there are different types of Bigfoot-like creatures. For instance, the "skunk ape" of the south is smaller and slimmer than the robust sasquatch of the west and north. The "dog-faced" type is another and, I believe the Alma of Russia is a primitive man. I also believe the small (compared to Bigfoot) Oran-pendec of southern Asia is a monkey or ape relative. So not only are we looking at different sizes and features, but also different species.
There were many types of primitive man. Perhaps some remnants still exist. And perhaps other species have developed human-like characteristics.