Mollys Castle is an isolated butte in Utah’s San Rafael Desert near Goblin Valley State Park, rising about 265 feet above the surrounding terrain on the southeastern edge of the San Rafael Swell. Though labeled as a mountain, it is a remote summit shaped by erosion into a stark freestanding rock mass. Its geology links it directly to nearby Goblin Valley: a thin cap of Curtis Formation rests atop darker red Entrada Sandstone, the same rock that forms the valley’s famous hoodoos. Draining into the Colorado River basin, Mollys Castle stands out as a dramatic landmark in a sparsely populated desert landscape.