Pediocactus simpsonii

Pediocactus simpsoni is a widely spread species, occurring through USA areas from Rocky Mountains and west. It is adopted for the environment where one would not expect to see cactus - areas with permanent winter snow cover, where pine trees not yuccas grow.
The plant is pretty easy in culture, once it's requirements understood. Pedoicactus simpsonii gets most of it's year's water supply from snow melt. It blooms on southern slopes at the time when nearby north facing sides of the same hill are still under snow, and air is cool.