We definitely are in the dog days of summer. In Great Smoky Mountains National Park the temperature's been well into the 90s, and with the high humidity, well, you really do need to find a place to cool off. With that understood, here are Traveler's picks for Where to Get Wet in the National Park System.*

The asterisk, my friends, is to discount national seashores and national lakeshores. Those places are supposed to have great swimming and paddling opportunities. Why would they be in the National Park System as "lakeshores" and "seashores" if they didn't have a few decent areas to get wet?

No, this post is about the other units of the National Park System where you can escape the high heat of summer by swimming, canoeing, or kayaking. So with that housekeeping out of the way, let's see what we've got, in no particular order.

Great Smoky Mountains National Park. This place is oozing with water. Hike any trail and you'll more than likely be parallel to a creek, prong of a creek, brook, or stream by any other definition that it really won't take much thought to figure out just where you're going to end up wet. While most folks find stretches of Laurel Creek, and the Little River Gorge (particularly where the two meet at the junction of Laurel Creek Road and Route 73), perfect for climbing onto a tube and letting the current do all the work, there are countless options in this park. Why, while coming down the Anthony Creek Trail the other day I saw more than a handful of enticing, boulder-rimmed pools to cool off in. Beyond that, there are said to be some nice spots along Big Creek in the northern portion of the park that make a hike worthwhile. Heading over to Deep Creek above Bryson City has its watery rewards, as well.

Yellowstone National Park. OK, this is a long-time favorite park of mine, so it shouldn't surprise anyone to see it on this list. But there really are some great places to cool off, places where it's not illegal to stick your foot in the (hot) water. Perhaps the main attraction for swimmers is the Firehole River where it courses through the Firehole Canyon. There are some nice pools here, but you also have to be careful with some of the rapids that could pose some serious problems. For the backcountry connoisseur, there's no place like "Cascade Corner," where you can ease your weary body into the simmering, geothermally-plumbed pool known as "Mr. Bubbles" found along the Bechler River. Another option is the so-called "Boiling River," a section of the Gardner River where a hot spring empties into the main stream and you can soak your bones. The park's lakes definitely hold plenty of water for cooling off in, but we're talking really, really cold water that takes some getting used to.

Yosemite National Park. While going down the Merced River in Yosemite Valley as if it were some Lazy River amusement attraction isn't for everyone, families certainly seem to enjoy it. Those more determined for a more, shall we say serious, splashdown hike to the top of Nevada Fall and cool off in that shimmering pool formed by the Merced River before it plunges into the valley. Still others, not bothered or embarrassed by the, ahem, effects of cold water might opt for Tenaya Lake.

Zion National Park. Red-rock doesn't normally conjure images of refreshing pools, but this park has a few if you know where to look. The most obvious is the Virgin River itself, and if you hike the river north of the Temple of Sinawava you'll find plenty of places to refresh your sweaty bones. Those who know a little about the park realize that one of the better swimming holes takes a little hiking, like down into the Kolob Canyons corner of the park where you can camp along La Verkin Creek and enjoy an apres dinner dip. Campsite 8, I believe, is the one close to a formation in the creek that creates a Jacuzzi-like tub. Enjoy.

Grand Teton National Park. The Snake River is the main aqueous attraction here, but something a tad more subtle is often more appreciated. String and Leigh lakes are both well-known for their relatively warmer waters. String Lake is the warmer of the two, thanks to its relatively shallow (nothing deeper than 10 feet here) water. The big lake, Jackson, has waters that can be tolerated, but not everyone likes the power boats that rip it up.

Sequoia National Park. They say drowning is the No. 1 cause of death in this park, but that doesn't mean you can't cool off, as long as you do it sensibly. One area that's popular is near Hospital Rock, which is about 6.5 miles inside the park's Ash Mountain Entrance. From the rock there's a short trail that leads to the Middle Fork of the Kaweah River where there are some inviting pools.

Glen Canyon National Recreation Area. If you can't find the water here, your eyes must be closed. This NRA was formed around that reservoir-known-as-Lake Powell. You can houseboat here, sea kayak, canoe or hike with a water-side campsite every night. If you head here, take the time to explore the watery backcountry, escape the crowds and find a secluded side canyon, preferably one with some hanging gardens.

Little River Canyon National Preserve. OK, getting wet doesn't always mean by swimming. Little River Canyon might only cover roughly 14,000 acres atop Lookout Mountain in northern Alabama, but the river packs a lot of wallop for experienced kayakers. Said to have carved the deepest canyon (roughly 600 feet) in the Southeast, and offering the cleanest water in the region, the Little River boasts rapids ranging from Class III to Class VI that lure paddlers when spring runoff hits. During the summer there are plenty of sand-bottomed pools to cool off in.
[url=http://www.nps.gov/ozar]
Ozark National Scenic Riverways.[/url] Two spring-fed rivers, the Current and Jacks Fork, became the first protected wild river system in the United States back in 1964. Not only does this unit protect nearly 81,000 acres of the Ozarks in Missouri, but the rivers offer a combined 134 miles of paddling terrain. you can enjoy the water at one of the designated campgrounds, or by heading to a primitive campsite somewhere along the rivers.
[url=http://www.nps.gov/obed]
Obed National Wild and Scenic River.[/url] Whether you're canoeing, kayaking, or just plain swimming, there's plenty of water here to counter the heat. The National Park Service likes to say that the Obed Wild and Scenic River, which can be found in Tennessee, looks much as it did "when the first white settlers strolled its banks in the late 1700s." As with many NPS properties, there are no lifeguards here and the park officially recommends against swimming. But in the dog days of August, a cool, shimmering pool can be hard to resist.

Now before you accuse me of overlooking your favorite swimming hole (or thanking me for not divulging your favorite swimming hole) or paddling spot, at Traveler we fully realize there are countless great places to get wet in the National Park System. Care to share yours?