Their dams give really good supplies like Pearls, cementing paste, mushrooms, etc. Put a bed near the beaver dam, go collect your items from the beaver dam, watch yourself die. Then respawn at the bed and collect your items from your dead body. Otherwise if you go up to a beaver dam and try to get supplies they're just going to kill you and you'll lose your stuff. If you bring a dino, leave it on passive as the beavers are very vicious and can easily kill anything especially since they're in groups.
If you are looking for a safe place with no carnos or allos around the beaver dams, you've come to the right spot. I play on Ark mobile and i live in the Southern Isles. Here are the coordinates for which i find my beaver dams: Lat 98, Lon 58. Also, heres a tip if you don't have a pteranodon. Just bola the beaver and shoot it in the head with a bow. I got a really strong bow from the pursuit Hunt: Dilophasaurus and it works well on the beaver. I suggest doing the pursuit if you are a beginner to get the bow. 30 arrows should do it for a small level. I hope this helped! Like so that beginners can see!