I'm confident that sasquatches thrive best in rainy forest habitats along with black bears, but away from the more open, arid brown bear habitats.
if I remember correctly, you live in Southern California, which us where I was born and raised. I remember being surprised to learn that the San Gabriel Mountains were devoid of black bears prior to the extirpation of brown bears, but they immigrated into the range quickly after the brown bears were shot out. I think that is an illustration of how quickly one species can make hay after a competitor is eliminated.
The Alexander Archipelago in Southeast Alaska is another illustration of range separation. Admiralty, Baranov, and Chichigof Islands at the north end of the chain all host brown bears and no black bears, but Prince of Wales, Revillagigedo, Etolin, Kuiu, Kupreanof, Annette, Zarembo, and Mitkof Islands at the southern end all host black bears, but no brown bears. It would be easy for bears to swim back and forth, but it doesn't happen. Significantly, sasquatch reports are more prevalent on the islands hosting black bears.