Hawk Mountain

We were at Hawk Mountain on Friday. It was rainy and drizzly but we got to see some fall colors. We went half way to the North Lookout before we got rained out and the kids got too tired. Hawk Mountain Sanctuary is a non-profit organization. There is a non-profit organization that runs Sugarloaf Mountain here in Maryland. The striking difference between the two is that Hawk Mountain charges trail fees while Sugarloaf doesn't. However, it seems like hiking on Hawk Mountain is done by the honor system since no one stopped us to ask for our tickets. I am wondering why the difference -- in one case charging and another case not. For instance, what if I wanted to know the size of the endowment of the non-profit organizations that are running these nature parks -- where can I look?