KEYSTONE — Three hours after dark fell on Summit County during a vigorous January snowstorm, most skiers and riders were wrapping up runs in 3 to 4 inches of freshies under flurries that shimmered in the slope-side lights. Near the bottom of the mountain that boasts Colorado’s largest night-skiing operation, Dillon residents Ryan and Jessica Grafmiller were finishing off their last run with their 4-year-old daughter, Olivia. It was Olivia’s first time skiing without Edgie Wedgies attached to her tips to assist her in holding the pizza position, and she made it top to bottom — all 2,200 feet of Keystone’s vertical drop — on the 3.5-mile Schoolmarm run. “She did awesome, we’re proud of her,” Ryan said.