The Arkansas River in Colorado is one of the best rivers for whitewater rafting in the U.S., and the most challenging stretch is the Royal Gorge, running through a narrow canyon with 1000 foot walls. The Arkansas is also the most popular river, and is crowded from May through September. The folks who aren't actually on the river are usually watching it from the suspension bridge over 1000 feet above.

With its long stretch of class III to V rapids, the Royal Gorge has unbeatable whitewaters. There are plenty of named rapids, like the Sledgehammer, Boateater, and Wall Slammer, giving you an idea of what the unnamed ones are like. Besides rapids, you'll hit narrows, big holes, high waves, and lots of steep drops into pools. The highest, coldest flows are in May, when the snow-melt from the Rockies heads down the Arkansas River from the Continental Divide. If the flow is higher than 3200 cfs, rafting is prohibited through the Royal Gorge, and you'll be rerouted to a safer run.

Dozens of rafting adventure companies are happy to provide rafts and guides if you're flying in and can't bring your own gear. They all provide helmets, wetsuits and life-jackets, but some charge extra for use of their gear, so be sure to read the fine print. Most won't accept anyone who doesn't have at least Class III experience for the Royal Gorge whitewater run, so if you have beginners or kids in your party, plan on an easier route like Bighorn Sheep Canyon.

If you want to raft on your own, be aware that recreational use of the Gorge is regulated by the Arkansas Headwaters Recreation Area, and if you put in at any of the possible sites upstream, you'll have to pay a fee for daily use.

After May, it gets really hot in the area, so wear something cool like this Topanga tank from Columbia, that's fast-drying and has UV protection, and these comfy shorts from Cloudveil. Make your feet happy with Salomon's Techamphibian 2 shoes that convert to sandals. And don't forget the sunscreen.

Some of the best whitewater runs are in the Carolinas. Two great runs can go together for an overnight trip on the Little Tennessee River in North Carolina.

The Little Tennessee, or Little T, starts as a creek in Georgia, then flows north into North Carolina, becoming a full-grown river. It flows between the Cowee Range on the east and the Nantahala Mountains on the west, and north until it reaches the Fontana reservoir. You'll see farmland and forest the first day, and mostly forest the second. Part of the river flows through private land, so make sure to get permission before camping.

Put-in the first day at the NC 28 bridge by Iotla, and take-out at the Lost Bridge, also on NC 28. You'll have smooth paddling; this 10-mile stretch is rated Class l-ll. You can run it in about 4 ½ hours, or longer if you linger. Towards the Lost Bridge you'll encounter shallow ledges that most beginners can handle.

Start the second day at Lost Bridge. This 13-mile stretch is way more fun than the first; its 13 miles are rated class ll-lll. When the river is high, there are several ledges that you should scout and run carefully; all can be spotted from the boat. When the Fontana is low, there are about 250 yards of ledges. Before the dam, this stretch was called the Narrows, and you'll want to stop and scout out before proceeding; at the bottom of the Narrows, the standing wave can hit 5 feet. If the water is low, scout left; if high, scout right. Take-out just before the US 19 bridge.

For the trip, take a craft that can store your pack and a sleeping bag. This shirt from Columbia provides sun protection and is quick-drying; you can choose to roll up the sleeves or keep them down. These Mission Playground shorts will keep you cool and comfortable. Wear a good pair of kayaking shoes and don't forget your shades; that Carolina sun is bright. A good water-proof watch can come in handy, too. Enjoy yourself, and thank your driver.

(Sources: Benner, Bob and David Benner: Carolina Whitewater: A Paddler's Guide to the Western Carolinas. 2005 edition, Menasha Press, Birmingham, AL; http://www.riverfacts.com/rivers/12402.html )

Women, despite allegedly having less upper body strength than men, are just as capable of learning to kayak and run rapids. Once you've learned, you'll be looking for runs that fit your level of experience and ability, and you'll want to have the right gear.

Two things you must know before you go are, first, the most current conditions and safety warnings for the run you've chosen. You can't rely on a guidebook to say what that river is like now, and whitewater paddling can be deadly. Second, no matter how experienced you are, you must wear a flotation device and a helmet. Nobody's head is rock-proof.

This week's river is the upper Baptism River in Minnesota, a Lake Country river that flows into Lake Superior. The upper part of the river is easier than the lower, although still rated moderately difficult, and if you put in at Finland and take out at Eckbeck, about 5.5 miles total, you'll have a pleasant day trip, with great scenery and lots of wildlife to watch. Since this is not quite Northern Minnesota, and has daytime highs normally in the 70s, you can probably wear shorts, but given the unreliable nature of Minnesota weather, you may want to bring long pants and a jacket too. A good pair of Tevas like these in a variety of colors will complete your clothing for a one-day trip. Consider taking a dry bag to keep your items dry.

The upper part of the Baptism consists mainly of class II to III rapids, with a few incidental holes big enough to hold your kayak, so go around them, generally river left. The only real exception to this is a large class IV-V falls in the middle of the run. Keep your eye out, as it's boat-scoutable, and if you're not class V material, take the kayak(s) out and go around it, and go back in below the falls. You'll have a pretty easy run the rest of the way, with a few class IIIs to keep you alert.

Next time, the lower Baptism!

When you're thinking of challenging rivers to canoe or kayak, North Dakota is not generally the first state that comes to mind. But there's a stretch of the Missouri, north from the capitol city of Bismarck to Garrison Dam, that could change your mind about Dakota waters. This stretch is one of the last remaining undeveloped segments of the Missouri. Peppered with sandbars and undertows, and with a remarkably swift current, this run is largely unchanged from the Missouri river the Lewis and Clark expedition followed in 1804. New sandbars, different logs and snags, but the same tricky river!

In addition to the thrill of the water, you're also in a prime spot to see both bald and golden eagles, beaver and white-tailed deer, and osprey. You may also spot endangered least terns and threatened piping plovers on the sandbars; if you do, don't disturb them; just take a photo, and paddle on.

If you didn't bring your own, you can find rental canoes and kayaks in Washburn at the Lewis and Clark Canoe and Kayak rentals, or at the Cross Ranch State Park (worth a visit even if you don't need a canoe), and at several locations in Bismarck and Mandan.

You'll want a dry bag to store your camera and other items. Good choices for canoeing footwear are these Columbia Hydrotooth shoes for men, and Columbia's Bellafly for women. The new Life is Good shorts are great summer styling for guys, and these Patagonia Board Shorts for women in plum make a fashion statement while keeping you comfortable. If the day gets chilly, women may want to bring along these Torrent Pants by Isis. Because it can get cool on the water almost any time from May to October, bring along a jacket, such as a Merrell Storm Jacket for men, and this Marmot PreCip jacket for women.

Another advantage to canoeing the Missouri is that costs in North Dakota tend to be lower than other areas. You can find great deals on food, hotels and canoe rentals in Bismarck, Mandan, and Washburn..