So you're not thrilled with sleeping on the ground in a tent, and you can't afford your own cabin in the woods? Step into a "camper cabin,'' a rustic, one-room cabin that provides a roof over your head, a table, benches and wooden bunks. Bring your sleeping bag. And sense of adventure. There's no Jacuzzi, big-screen TV or even running water or a bathroom (public toilets are nearby) -- but the sights, sounds and smells of nature are at your doorstep. Seventy-nine cabins are available at 25 of the state's 75 state parks and recreation areas. Our favorites are the six cabins at Wild River State Park, just north of the Twin Cities. Most are just a few hundred feet from the sparkling St. Croix River. Cost: $45 without electricity; $50 with.