Most definitely a Savage 99 and if you take a good hard look, I am willing to bet those are Bean boot-pacs or something very much like 'em! Nice shirt too, looks like wool.
You can see the cartridges in his belt are bottle-necked, so chances are his 99 is chambered to either .303 Savage or "thutty-thutty". There are two other possibilities, .22 Savage High Power, also known as The Imp, or .25-35, but the slugs look larger than either of those rounds.
Sam, all these photos have been especially neat, but the very first and this last are standouts. I love seeing pictures of fellows hunting and prospecting back when men were men and toilet paper was scarce on the ground! :wink: