After 14 summers excavating in Yellowstone National Park, Doug MacDonald has a simple rule of thumb. “Pretty much anywhere you’d want to pitch a tent, there are artefacts,” he says, holding up a 3,000-year-old obsidian projectile point that his team has just dug out of the ground. “Like us, Native Americans liked to camp on flat ground, close to water, with a beautiful view.”
We’re standing on a rise near the Yellowstone River, or the Elk River as most Native American tribes called it. A thin wet snow is falling in late June, and a few scattered bison are grazing in the sagebrush across the river. Apart from the road running through it, the valley probably looks much as it did 30 centuries ago, when someone chipped away at this small piece of black glassy stone until it was lethally sharp and symmetrical, then fastened it to a straightened shaft of wood and hurled it at bison with a spear-throwing tool, or atlatl.