Hi i was wondering if its possible for me to go there with my metal decctor and look for metals or Would i need a premit or i have to pay?

I think you definitely would have to ask them

Its public land so you are able to do whatever you want there except for Excavating large material stop by the friends of Jawbone station close by there and get a map so that you'll know when you are on public lands because there is a mixture of property lines such as State Property private property and public lands