Any public land is available for top surface pick up finds only. No digging. Federal law.
I suggest going down to your local creek and walking it. Look at the beach's of cobble stone and arrowheads often times get washed out of the dirt and land on those little beach's past each eddy. Lots of points in the creeks of America. Mostly legal to pick up as well if they have been displaced by water in a creek/river.
