Thats why I never bring my wallet or keys into a park.
I have a door key in my pass holder on my lanyard, a keypad door lock put on, spare key in my camera bags, and a hide a key if need be. Also I am going to have my GF sew up some parahute clips on some cargo shorts for my phone to make sure it stays in my pockets.
Side note some wrangler shorts I bought came with a D ring sewn in to the belt loops, cool for keys and IDs.