Red Fleet State Park in Utah is a fascinating place, as it is home to some incredible fossils such as dinosaur tracks that have been preserved for 200 million years. The only problem is that dumb tourists have been tossing these rocks into the lake, and it is completely frustrating local authorities.

These are not pebbles, but rather huge stone slabs that require a lot of effort to toss in the nearby reservoir. The Salt Lake Tribune reports that there has been a big rise in this vandalism.

“It’s become quite a big problem,” Devan Chavez, a spokesperson for the Utah Division of State Parks, told the paper. “They’re just looking to throw rocks off the side. What they don’t realize is these rocks they’re picking up, they’re covered in dinosaur tracks.”

Essentially, it has become too tempting for visitors to toss some giant rock into the reservoir below to get a satisfying splash. So they grab the closest thing available, which happens to be portions of a fossilized trackway. The vandalism has gotten worse in recent months, and as a result many priceless fossils have been lost forever.

It has gotten so bad that the park is even considering hiring a diving team to swim to the bottom of the lake and try to find some of the pieces. But they know that the rocks are likely destroyed in most cases. So for now, they are resorting to warning signs in the hopes that the unwitting tourists will wise up.

“The dinosaur track site is deteriorating due to human impact,” the park wrote on their Facebook page recently. “There has been a substantial impact to the track site from individuals throwing rocks (most containing dinosaur tracks) into the water over the past 6 months. People come to our park from all over the country and world to see this amazing feature. It is not illegal to throw rocks into the water, it is illegal to displace these rocks which contain tracks. Be aware disturbing these rocks is considered an act of vandalism. Many tracks are very distinguishable to the lay person but many are not. This is why it is so important to not disturb ANY rocks at the dinosaur track-way. You may not be able to tell if the rock you are tossing has millions of year old dinosaur tracks imprinted in it or not.”