The Treasure State’s unique geology makes it a rockhound's dream, but a Big Timber man is still trying to figure out what he found eight years ago while hunting for rocks on the banks of the Yellowstone.

“I’m wanting to put the mystery to bed after eight years. It’s been long enough,” says Dillon Perry.

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The mystery he is talking about is a nine-and-a-half-pound hunk of something. No one is quite sure what, but Perry believes it didn’t come from this world.

“It’s out-of-this-world crazy,” he says.

Perry made the discovery while hunting for agates along the Yellowstone River near Greycliff.

“It was buried in the sand just a little bit poking out and the sun shining just right and I noticed that color green kind of poking out at me,” he says.

The greenish glow is just one of the odd qualities.

“I washed it up, brought it home and stuck a magnet to it,” he says.

And when the magnet stuck, Perry says that sent him down a rabbit hole trying to figure just what he found.

“It just started bugging me. I’ve done research on it since the day I found,” he says.

“I’ve had XRF tests done on it. I’ve had a portion of it cut. I’ve done scratch tests. I’ve sent off pieces of it to really smart people. They told me they thought it was a meteorite,” he says.

Perry also suspects that is what the mystery rock is and he’s done a lot of studying about them since he made his find along the banks of the Yellowstone.

“It’s definitely something different,” says Ennis Geraghty. Geraghty spent decades as the chief geologist at the Stillwater mine and says he’s never seen anything quite like it.

Geraghty says one thing is clear. Whatever it is, it didn’t come from around here. But did it come from another world?

“It needs to be tested that’s the final step. It’s definitely different than anything I’ve seen,” he says.

So, for now, the mystery remains.

“It’s just weird. Everything about this rock is weird, so I’m hoping I get some answers to it one of these days. Eight years is long enough,” Perry says.