Hours: The caldera can be accessed late Apr.-Oct. 31 (weather permitting). In winter and early spring visitors can drive 10 miles toward the caldera and then must either snowshoe, snowmobile or cross-country ski the last 3 miles to view the caldera; phone for additional information about access. Paulina Visitor Center open daily 9-5, mid-June through Labor Day; daily 10-4, day after Labor Day-Oct. 1; Sat.-Sun. and holidays 10-4, Memorial Day through mid-June. Phone ahead to confirm schedule.