Beaver Bowl is an exciting chunk of terrain in our "NEW" Beavers area. I say new because it has been considered part of the ski area in the past. Below is a trail map from 1958. Unfortunately, the resolution is not great. If you look at the far right side of the map you can see #13. The key identifies #13 as Beaver Pond Run. I have other maps, one dating to the 1940's that also identify Beaver Pond Run. If you ski the line outlined as #13, you eventual end up in the beavers ponds in the valley bottom.
In the early days of Arapahoe Basin, the concept of exact ski area boundaries was different than it is today, but the Beaver Pond Run has been an integral part of The Basin since the beginning, 70 years ago. Over time, the name has been shortened to simply The Beavers.