Do the mountains speak to you? In Yellowstone, at least one mountain hisses.
Roaring Mountain looks like a smoking mountain, especially on cool mornings. It is a hillside full of steaming fumeroles. The escaping gases and steam rumble and hiss to create the sound you hear.
In 1885 it was loud enough to be called Roaring Mountain. More recently however, the activity and noise is less intense.
The steamy slope displays the hottest of Yellowstone’s thermal features: fumeroles. They have less water than hot springs and geysers, so the heat immediately flashes any water to steam before it can pool at the surface. Acid sulfate in the steam emissions have crumbled and bleached the rocks, giving Roaring Mountain its gray-white ashy appearance.
Stop and listen for a while, but remember steam and acid can burn, so don’t get too close. Come back to listen in a few years. Perhaps the mountain will roar once again.