national park, national parks, sand, dunes, winter, snow, colorado, valley, daytime, snow-covered, tree, soil, plant, ridge, district, state, snow-clad, sand dune, dune, american state, woody plant, woody_plant, daylight, weather, season, earth, precipitation, day, commonwealth, speed, ground, dirtiness, twenty-four hours, territory, dirt, nation, hurry, land, temporal property, pace, haste