For a pinch-yourself experience of outdoor splendor, launch your canoe into the St. Croix up by Taylor's Falls in early October and paddle downstream 30 miles to the William O'Brien State Park near Scandia. Stands of sugar maple should be peaking crimson, orange, and yellow. Bald eagles and osprey will be wheeling in the air above and alongside the steep bluffs. The current in this stretch of river, while not as turbulent as the upper end of the St. Croix, offers alternate periods of alert exertion and relaxing serenity. Small tributaries or side channels braid into the main river, offering beguiling detours and island rest stops. If you can't wait for fall, check the strength of the spring runoffs, then coast by blooming wildflowers along the shore. Or wait until the summertime heat, when the water meanders. The sandy bottom of the lower St. Croix will save the deposit on your canoe rental, or the precious bottom of your own boat. And it's all less than an hour's drive from the Twin Cities.