On a bright morning in late June, Shirl Ireland stands in her backyard painting majestic Mount Sepulchre, which rises from the northern edge of Yellowstone National Park.

This kind of outdoor painting, called plein air painting, is quite difficult, as it must be done in a couple hours or less. “Plein air painting is a sport,” says Ireland who has long brown hair with streaks of silver, and an earnest, quiet intensity. “You have to get it down quickly before the light changes.”

“Yellowstone is an amazing place to paint,” she continues, using white oil paint to capture a bit of snow that still clings to the peak. “I’m not sure there are many places on