This is a very sluggish documentary which wastes almost a full half hour of its start just going over the generic UFO documentary routine that you're likely to see better and more coherently done elsewhere.
By the time it gets to its supposed Bigfoot/Alien connection, it completely abandons any sense or attachment to reality, essentially claiming that every random Bigfoot fact is proof not that Bigfoot exists, but that Bigfoot is an alien.
I'm neither a believer in Bigfoot or in UFOs visiting Earth, but the conclusions being drawn here are so insane and absurd it actually makes me defensive about Bigfoot research.
The "Sierra Sounds" recordings by Ron Morehead were featured in a different (and far superior) Bigfoot documentary as proof not just of Bigfoot but of a level of sentience in Bigfeets as well as having evolved the capacity for complex language.
This documentary, in the space of about 30-40 seconds, flatly claims that the Sierra Sounds are proof that Bigfoot is alien, because apparently only aliens can talk. Nothing further is elaborated as to how this non sequitur is somehow conclusive proof of a Bigfoot/Alien connection.
Other examples given border between wild to complete and pure fantasy, such as implying that Bigfoot is an alien because Bigfoot teleports somehow. People see Bigfoot, then turn around and see Bigfoot behind them. This, they claim, is proof Bigfoot can teleport, because there's absolutely no way there would be more than one Bigfoot walking around together.
At one point late in, they completely give up and start talking about EVP, moving on to ghost stuff for no reason.
The level of illogic is overwhelming even for a documentary about Bigfoot and UFOs. It is the equivalent of saying "Horses are secretly stealth aircraft from an alternate universe because they can't be detected on radar."