My experience has been interesting. Several years ago I went by the local BLM office to inquire about shooting on BLM land near where I live. I wanted to be sure htere were no restrictions of any kind on the area where I wanted to shoot.
I spoke to one of the enforcement rangers, and she very courteously told me that that was "my" land, and I could do whatever I wanted, as long as I was safe and didn't endanger anyone else. She even took time to pull down a map and show me several good places where others shoot, and said to have fun.
Fast forward a couple of years. I was out with my wife and another couple shooting, and another enforcement ranger pulled up to where we were shooting to see what we were doing. He looked at our guns and commented on them, compared my Beretta to his pistol, and said have a nice day. He also gave us several trash bags and asked us to pick up our trash when we left. We already had one of our own bags filled up and showed that to him, and he thanked us for the clean-up detail.
That's the way encounters with LEOs should go. Very professional and courteous.