When snow buries Crater Lake National Park [1] in the wintertime, services and activities are cut to a minimum. However, many cross-country skiers, snowshoe enthusiasts, and winter campers enjoy this solitude. Park rangers lead snowshoe hikes (weather permitting) at 1 p.m. on weekends, daily during Christmas week. Ski and snowshoe rentals are available at Rim Village.
Winter trekkers should be aware that there are no groomed cross-country trails, so it’s imperative to inquire about trail, avalanche, road, and weather conditions at the visitors center (8:30 a.m.–4:30 p.m. daily). Circumnavigating the lake, which is visited by frequent snowstorms, takes 2–3 days, even in good weather. Only skilled winter hikers should attempt this 33-mile route that requires a compass and maps to traverse unmarked routes and avalanche paths.
Prior to setting out on any extended backcountry journey, pick up a permit and some free advice at the visitors center. You might also inquire about a hike to the top of Mount Scott (8,926 feet), the highest peak in the area. Lake views and perspectives on 12 Cascade peaks are potential rewards at the end of the 2.5-mile trek.
There are no overnight accommodations in the area mid-October–June (and you are not allowed to sleep in your vehicle), necessitating a long drive out of the park at night.
Links:
[1] http://www.moon.com/destinations/oregon/southern-oregon/crater-lake-national-park