HOT SPRINGS - When it comes to fish stories, David Brown has one that will be tough to top. And he has the proof to back it up.

Brown was preparing to do a bit of landscaping around his house in the Country Club Estates subdivision south of Hot Springs. Like many do-it-yourselfers, he ordered a couple of pallets of reddish limestone from Landmark Stone to complete a retaining wall.

But that is where the story takes a turn.

"I was just unloading the pallet and came across this rock," he says, pointing to an ordinary looking piece of limestone with an impression on it. "It was hot, like it is this afternoon, and I had sweat pouring into my eyes. I thought that it was one of those nylon vegetable bags stuck to the rock."

When rubbing on the rock failed to remove the white spot, Brown said he looked more closely at it and realized it was something more defined.

"I said 'Whoa, that's a fish!'" Brown said.

More precisely, a 260 million-year-old fossil of a fish. That's according to Dr. James Martin, the executive curator of the Museum of Geology at the South Dakota School of Mines & Technology in Rapid City.

"What David found appears to be a palaeoniscoid fish, a primitive ray-finned fish, which was within the group that may have given rise to later ray-finned fish, such as herrings and minnows," Martin wrote in an e-mail.

Brown's discovery is unique in that there appear to be scales embedded in the rock, and, where the scales are gone, amazing definition remains. One can easily see ridges from scales and bones in the rock. The specimen is about 6 inches long and is only the front portion of the fish. Proportionally, the tail section could be on another rock somewhere.

"I haven't gone through the rest of the pallet," Brown said. "Maybe it's in there, but the chances are that it is on a piece of limestone somewhere else, if it wasn't broken already."

Martin's note goes on to say that the Minnekahta limestone in the area dates to the Permian Period, about 260 million years ago, when a shallow sea covered most of western South Dakota. Landmark Stone had quarried the stone in Steve Simunek's quarry in Shep's Canyon south of Hot Springs.

Brown, who said he is a bit of a rock hound, was very excited to find a fossil of this magnitude. "I transferred here with the VA from Minneapolis about three years ago," Brown said. "Before that I had lived in the mountains of Colorado for some time, so getting back to mountains, particularly ones with a history of fossils was a goal of mine."

Brown said that he often heads toward Angostura with his dogs for some fossil hunting.

"I've found lots and lots of rocks with clamshells in them," Brown said. "They're all over the place. But this makes up for all of those clamshells."

Brown will be transporting the rock to the geology department at the School of Mines. "I understand that there is a student there who is very interested in doing research on it," he said. "I think he plans on doing a thesis on it."

While the retaining wall project will be completed, it's safe to say that this particular rock will not be used.

"I have some friends who said to use it on the top, so it could still be seen," Brown chuckled. "But I think that something like this will find a more specialized place when studies are completed on it."