around here, yeah you might get shot trespassing. and a heads up to the original poster about 4 wheelers, i have a friend who has quite a bit of property in a pretty populated area (near tampa, fl). he is CONSTANTLY dealing with atv's running through his property, many times destroying property and definitely scaring away wild game which he does hunt often (he pulls wild boars out probably no less than 1 month and they're still rampant!). it is vastly better to go on a bicycle for this sorta thing as it draws less attention, you could always have a map and play the looking for a shortcut, sorry, thing, but the atv is outright trespassing "for fun" or whatever and it draws a lot of attention.
not sure what state you live in, but in florida if they are on your property and you get them trespassed there are legal avenues the owner can take and can legally confiscate whatever equipment you brought on his land (ie your truck, trailer and atv if they were all on his land). maybe your state is different. also, we're a "castle doctrine state" which means your home is your castle and you can defend it accordingly, and some folks do. better to be on a state park, and i know most people think they're over run but private property you need to have a good way in and out if it's someones homestead because they'll be there and if they see you call the cops or worse.
anyway, just a heads up bro, good thing you didn't get worse, a lot of farmers might have one or two kids giving them a hard time on atv's then here you come and they take that pent up anger out on you, because to them you're just another one of the atv riders spooking his cattle.