Murrayhill is managed by CMI and not a "park" so while it may be allowed, it could quickly not be allowed. All that has to happen is one business to complain and signs will go up. So be respectful, pack out your trash and be discreet if at all possible.
I only say all of this because I have fished there and had a lady yell at me because I could possibly hook a duck or turtle. She claimed I could not fish there. I did my homework and made some calls and got a "there are no rules that say you can't fish there, but there isn't anything that says you can", so again, play nice while there or very quickly no one will be allowed there.
I have picked up a lot of fishing line, bags, cans and seen a lot of trampled bushes.