HOW LONG: Four days, 90 miles
WHEN TO GO: July to September
EVEN BEFORE YOU get to the put-in at Murder Lake, you'll be stunned by the floatplane views of the Talkeetna far below, cutting a white line through the Alaska Range. Offering an unmatched density of wildlife, whitewater, and epic landscape, the trip starts with a whimper on little Prairie Creek, but soon cranks up to a roar. You'll charge 90 miles, skirting Denali National Park, to your take-out at the confluence of the Susitna. Cowboy up for 14-mile Talkeetna Canyon, where the Class IV Sluicebox will batter you for ten miles, one of the longest commercially run rapids in North America. When you relax the death grip on your paddle, watch feeding grizzlies, hook Dolly Varden trout, and crowd-surf on the backs of spawning salmon. »OUTFITTER: Class V Whitewater ($1,200; 877-783-2004, www.alaskanrafting.com) »DIY: No permit required; no rentals available. Serious paddlers must haul their gear to Willow, Alaska (71 miles from Anchorage), where Susitna Air will fly four people and equipment to Murder Lake ($545; 907-495-6789).
HOW LONG: Upper Gauley, one day, nine miles; Lower Gauley, one day, 17 miles
WHEN TO GO: September to October
"YOU CAN ALWAYS tip over, but you can never overtip," goes the old guide's maxim. On the Gauley, guides have turned that adage on its head: "More flips equals bigger tips." Each September, releases from the Summersville Dam pump flows up to 2,800 cubic feet per second, attracting more than 50,000 river runners for ass-smacking Class IVV action. Rapids like the Upper Gauley's Iron Ring and Sweet's Falls, which begin as dull roars on the horizon line, are as close to pro bull riding as most of us will ever get. If that's too terrifying, the 17-mile Lower Gauley takes the tooth-loosening ride down a notch. Crowded? You bet. But the mist hanging in the fall foliage makes you feel happily removed from civilization. »OUTFITTER: North American River Runners offers a two-day trip, covering 14 miles on Saturday and 12 on Sunday ($270; 800-950-2585, www.narr .com). »DIY: Expert kayakers and rafters can put in at the dam, paddle to the take-out at Mason Branch, and self-shuttle.