Teddy Roosevelt National Park

One of the books I was reading on the trip was Peace like a River which talked about a family having a winter picnic in North Dakota in the snow next to a glowing burning river. I thought it was fiction until we discovered this trail in TR Park through an area that had lignite coal beds embedded in the rock. When Theodore Roosevelt lived in the badlands in the 1880s, he and his ranch hands shoveled lignite coal from the hillsides to use in their stove. Lightning strikes and prairie fires can ignite coal beds, which then may burn for many years. When a coal bed burns, it bakes the overlying sediments into a hard, natural brick that geologists call porcelanite but is locally called "scoria." The red color of the rock comes from the oxidation of iron released from the coal as it burns. The burning lends both color to the badlands and helps to shape them. These hardened rocks are more resistant to erosion than the unbaked rocks nearby. Over time, erosion has worn down the less resistant rocks, leaving behind a jumble of knobs, ridges, and buttes topped with durable red scoria caps.