The Eastern Timber Rattler is definitely present on Buck. There are not a lot of them, but a dog sniffing around logs and behind rocks is much more likely to discover one than a hiker.
Sorry about the brain cramp. I was thinking Tongue when you asked about Buck.
While I've been on both many times, I know Tongue has them and don't know anyone who has seen one on Buck.
I have heard about snakes on Black Mt., and of course the Tongue, and it wouldn't surprise me if they're on most of those Lake George Mts. However, we've been on all of them multiple times and have yet to see a snake...but we don't have a dog. We're doing the Tongue loop next weekend, weather permitting.
There are 4 dens on Tongue mnt and 1 den on the east shore. The location of that 1 den on the eastern shore is a secret. You have about a zero chance of seeing a rattler on Buck. Have fun and don't worry.
Mike G.
PS- If you see one on Tongue, you are a lucky hiker.
I have seen 3 rattle snakes on Tongue and now avoid this area in the summer with the dogs. On all occasions the snakes were pretty close by the time I saw them. One even coiled and rattled! I have never seen any on the east shore in dozens of hikes but suspect there are a few.