Swish. Swish. Thunk. Swish. You've been going all night, and sunrise is very far away. But you keep going, going, because they expect you on the other side, because your mission cannot be delayed. Swish. Swish. Thunk. Thunk. The woods are dark and silent, but you are not afraid. This wilderness, after all, is your home, and no one--human or animal--can match you on skis. Okay, so you're bushed after 5K and your sweater is getting itchy, and you wonder about the next bathroom. But a person can dream, right? Especially on a full-moon night, when the park rangers allow intrepid visitors out onto the loops. Hennepin County Parks offer moonlight skiing at Baker Park Reserve in Medina and Cleary Lake Regional Park in Prior Lake; call (612) 559-6778 to check trail conditions. Ramsey County opens Tamarack Nature Center in White Bear Township to moonlight skiers and snowshoers; (651) 407-5350.