There’s a reason why the premier makers of monster single-action revolvers are here in Wyoming (Freedom Arms and John Linebaugh).
Even in the Big Horns, where we aren’t supposed to have anything bigger than cats, black bear and moose... I take a .45 while hiking or hunting.
I was raised near Wheatland, but still have a couple of bear stories. A local farmer heard his cattle in a feed lot bawling one morning. Went out and there was a black bear up a utility pole. He called the Game Warden to come and get the body.
I went elk hunting by Pinedale in about 1965 with my dad and a friend of his who had lost an arm in WW2. The friend came back to our little camp one day and started packing. He told my dad that a bear had followed him all day. He would walk and the bear would walk. He would stop and the bear would stop. The bear would loop around some and be waiting for him to pass through an area. He said that a man with two arms had little to no chance against a bear so what chance did a one armed man have? We did not get an elk that year.
I would suggest a .44 magnum at the minimum.