Leaning against the cart, I took a closer look at the hat. It was still in good shape, so it couldn’t have been here for years. Was it evidence of someone mining here recently? How remote was this place?

I called Holly over and held out the hat. “Find. Holly, find.”

Holly sniffed the cap, sat, and scratched her ear.

Placing the cap under Maverick’s nose made him sneeze. So much for search-and-rescue dogs.

Straightening, I examined the area again, this time paying close attention to the landscape.

The area where the geyser sprayed was rocky and without vegetation, which would make sense. A couple of bushes on the perimeter were dead, a few more farther away were dying, and a nearby ponderosa had turned yellow and dropped the needles on the lower branches.

Leaning on Maverick, I made my way toward a flat area of dead grass next to the creek. A round rock about the size of a softball caught my attention. When I picked it up, black soot came off in my hand. I dropped the rock and looked for more. I quickly spotted a number of same-sized rocks scattered around the area. Now that I was closer to the dead grasses, I could see they formed a square.

A campfire ring? The square outline of a tent? But no garbage, cigarette butts, tin cans. If someone had pitched a tent here, it wasn’t there long enough to permanently kill the grasses.

So the miner had gotten what he wanted after a short amount of time, picked up, and left, taking care to erase his presence. He would have to have known that mining this close to Yellowstone was illegal.

Of course, the chances of getting caught would be slim to none. If not for the dead vegetation, the opening would be hidden from above and from anyone coming up the gulch. So why—

Dead and dying bushes. If this geyser had been active for a long period of time, there would be nothing growing around it. The ground around Yellowstone’s Old Faithful was barren.

A seed of an idea sprouted in my mind. Again I replayed Grace’s comments. Yellowstone’s incredibly fragile geothermal pools and geysers can be destroyed or altered by man. For example, people routinely throw pennies, garbage, even soap into geysers and pools. This can change the direction of a geyser or . . .

Another thing could alter the course. Mining, especially mining that used explosives to loosen the rock. What if someone accidentally blew an opening into an existing vent? Once that happened, there would be no safe way to remove the ore. Maybe that’s why this place was abandoned—not because the mine tapped out but because it was too dangerous to work here.

The sun had shifted and was now directly overhead. I needed to move on. The killer could return at any time.