Go to your town web site and check park rules. If they do not say it is illegal to do then so it. It you start asking if ou can they will tell you no. So check the rules and you should be ok. I have never had a problem with any park that I have detected. Just make sure you cover your holes real good. Make sure you pratice on your lawn and to make it look like you can not see where you have dug. The more you dig the better you will get. If you have a problem with the dig on the grass. Take a piece of cloth with you and when you dig out your plug put it on your cloth then scoop out the loose dig and place that on the cloth also. When you find you target set the plug off and dump the loose dirt back into the hole then put the plug back in press it down with your foot and you proable will have a hard time telling where you have been. Good luck and happy hunting.....Matt