Alabama's longest free-flowing river is home to over 135 species of fish, which makes it an ideal fishing spot. It's also a great destination for paddling, kayaking, and canoeing.

The Chilkoot River is one of the most popular freshwater fishing sites in Alaska. It's especially known for its ample amount of pink and sockeye salmon (especially in July and August). The river is also a great place to spot wildlife like bears, bald eagles, seals, and goats. 

The Colorado River flows through seven states, including Arizona. There are four Arizona State Parks along the river (some of which feature dog-friendly beaches), where visitors can camp, boat, hike, or swim. If you're up for the adventure, you can also go rafting, kayaking, or tubing.

Thanks to its mild temperatures and beautiful scenery, the Ouachita River can be enjoyed all year long. Here, families and couples alike can go fishing, camping, hiking, birding, swimming, or boating. The slow-flowing river's average speed is just one mile per hour, which makes it a popular spot for tubing. Learn more about floating down the river here. 

Located in Northern California, the Feather River -- which flows through several charming towns like Quincy, Oroville, and Twain -- is the perfect place for fishing, boating, or kayaking. You may even spot wildlife like bears and bald eagles. While the fall offers beautiful foliage, springtime brings colorful wildflowers and lush greenery. The Feather River Canyon Scenic Byway route, which spans 130 miles in total, is also not to be missed.

The Poudre River is Colorado’s only nationally designated “Wild & Scenic” river, and it certainly lives up to its title. Enjoy postcard-worthy views as you kayak, canoe, or whitewater raft your way down the river (you can also fish here). When it comes time to dry off, embark on a scenic hike or bike ride.

This 47-mile-long river flows through Northwest Connecticut. It's known for some of the best trout fishing in all of the US. While swimming is not recommended, you can kayak, canoe, or paddle. Additionally, the Farmington River Tubing Company offers fun and family-friendly tubing excursions. 

The historic Delaware River flows through five states. From fishing to canoeing, the river offers something fun for everyone -- whether it's renting a kayak or embarking on a romantic sunset cruise. 

This majestic Florida river, which is home to dozens of manatees, features clear-blue waters and warm weather all year long. It's especially popular in the winter, when nearly 400 manatees migrate here from the Gulf of Mexico. For a bucket-list-worthy experience, embark on a swim tour through the river. (More info here.) 

The Chattahoochee River spans a whopping 430 miles and flows through the entire state of Georgia. It's a great place to fish, since it's filled with trout. Other popular activities include tubing, rafting, kayaking, and canoeing. Meanwhile, the Chattahoochee River National Recreation Area features thousands of acres of scenic trails.

This tranquil, 20-mile-long river can be found on the island of Kauai (known as "The Garden Isle"). It's surrounded by beautiful waterfalls and tropical jungles. Explore the river up-close via canoe, kayak, or stand-up paddleboard. If you're up for the adventure, take a guided boat tour of the Fern Grotto, a natural lava cave surrounded by lush ferns and foliage.  

Idaho's Snake River is an incredible destination for rafting, whether you prefer adrenaline-pumping whitewater rafting or mellow family-friendly tubing. The Snake River also boasts its very own wine country, which attracts oenophiles from near and far.

The Fox River is located along the outskirts of Chicago but feels worlds away from the hustle-and-bustle of the big city. Along the water, travelers can enjoy 30-plus miles of hiking and biking trails. If the weather's nice, you can fish, rent a boat, or paddle your way down the river. 

The scenic, 100-plus-mile-long Eel River is ideal for bass fishing (you'll also find catfish and bluegill). The river, which flows through several charming small towns, is also popular amongst kayakers and boating enthusiasts. If you don't have your own boat, you can rent one from Miller's Canoe Rental. 

The Missouri River is the longest river in all of North America. The river touches seven states, including Iowa. It also flows through downtown Sioux City, where travelers can enjoy scenic riverfront walking trails. While swimming isn't recommended, you can go fishing; in fact, the river is home to plenty of catfish, sturgeon, bluegill, crappie, and dozens of other fish. 

The Kansas River is chock-full of fun activities, including floating, canoeing, kayaking, paddleboarding, and fishing. Plus, since the river is dotted with over 20 public access points, it's easily accessible and simple to navigate. 

Known as the Houseboat Capital o the World, Kentucky's Cumberland River attracts visitors from all over. Here, you can fish, enjoy miles of scenic walking and hiking trails along the river, and go whitewater rafting or kayaking. The destination is also known for the majestic, 69-foot-tall Cumberland Falls (also known as Little Niagara). 

The expansive Red River flows through the city of Shreveport. In addition to hunting and wildlife spotting (think deer, hawks, and armadillos), you can also take a river cruise or go boating. Shreveport also boasts a lively riverfront area, where you'll find galleries, museums, and even a brewery (aptly named Red River Brewpub). 

The 190-mile Penobscot River is an outdoor enthusiast's oasis. It's best known for its striking scenery, dreamy mountain views, and excellent (albeit challenging!) whitewater rafting. If you'd rather partake in a more leisurely activity, consider kayaking or canoeing.

Explore all that the river has to offer at the bustling National Harbor in Prince George's County (right outside of DC). This 300-acre waterfront development complex is chock-a-block with shopping, drinking, dining, and entertainment options. Here, you can also rent kayaks, pedal boats, or standup paddleboards. If you'd rather not do the work, you can embark on a scenic sightseeing cruise. 

The Charles River spans over 80 miles. If you've never been to Boston and you're traveling with little ones, take a Duck Boat Tour for a memorable sightseeing excursion. Alternatively, take a sunset, happy hour, or architecture-themed cruise along the river with Charles Riverboat Tours. Or, if you're feeling adventurous, rent a kayak or canoe from Paddle Boston and explore on your own. 

The Huron River winds through Ann Arbor, Dexter, and Ypsilanti and offers all kinds of recreational activities, including kayaking, canoeing, fly-fishing, and stand-up paddleboarding. Experienced kayakers should paddle their way down the 104-mile Huron River Water Trail. 

Minnesota may be known as The Land of 10,000 Lakes, but it's also home to several rivers, too. The Temperance River, for example, is ideal for adrenaline junkies and outdoor enthusiasts. Around the river, you'll find plenty of scenic (albeit rocky) hiking and biking trails. 

The Mississippi River is the second-largest river in all of North America (it passes through 10 states!), which means there's plenty to see and do in and around the water. Popular activities include kayaking, boating, and fishing. The Mississippi River is also a great place for birders -- it's home to 300-plus species of birds.

Thanks to its crystal-clear waters, the Current River is ideal for tubing, kayaking, rafting, and paddling. You can also float down the river at a comfortable speed of around three miles per hour. After your excursion, enjoy a picnic lunch and admire the waterfront views.

The Flathead River offers Rocky Mountain views and beautiful scenery. Its beautiful blue-green waters are also great for kayaking and canoeing. You can also leisurely float down the river or embark on an adventurous whitewater rafting excursion (depending on what you're looking for).

This winding, 72-mile river is a perfect place to kayak, fly-fish, hike, or tube. Note that this is a fast-flowing river with plenty of twists and turns, so, while it's great for adrenaline junkies and experienced swimmers, you'll want to make sure you're up for the challenge. 

The Truckee River is popular amongst both locals and travelers for its kayaking and rafting opportunities. If you just want to swim in the river, visit Reno's Wingfield Park. Truckee River Whitewater Park is also worth a visit. 

This New Hampshire river boasts an abundance of trout, bass, and salmon, which makes it ideal for fishing. The water is calm enough to enjoy a leisurely boat ride or tubing adventure. Along the river, you'll find several sandy isles that make for great sunbathing spots. 

Also known as the Swimming River or North Shrewsbury River, this 8-mile long estuary in Monmouth County, New Jersey makes for the perfect day outdoors. Whether you're fishing, taking a dip in the water, or kayaking with a friend, the Navesink River offers fun for everyone.

This New Mexico river is surrounded by beautiful flora (like sycamores, willows, and cottonwoods) and boasts ample wildlife spotting opportunities (hawks, eagles, elks, and cougars can all be found here). You can also kayak, canoe, and raft through scenic canyons. 

The St. Lawrence River is dotted with over 1,000 islands (hence the region's name, Thousand Islands). Here, you can soak up the sun on one of the sandy beaches and take a dip in the clear (and clean!) water. Divers also have the opportunity to explore several shipwrecks that date back to the 19th century.

Paddling, swimming, kayaking, and fishing: Enjoy all this and more at the Catawba River. One of the best spots along the river is The U.S. National Whitewater Center, which offers a wide array of water sports to choose from -- plus ample shopping, drinking, dining, and entertainment options. 

The best way to experience the North Dakota Badlands? A float trip down the Little Missouri River, of course. (You can kayak or canoe, too.) The river is also popular among fishermen thanks to its large population of bass. And, if you're lucky, you may even spot a bison or two.

The Scioto River, which flows through Ohio's capital city of Columbus, is a fantastic destination for kayaking and fishing. Rent a kayak from Get Out and Kayak and enjoy the water; afterward, head to the city's vibrant Scioto Mile. 

The Oklahoma River refers to the part of the Canadian River that flows through downtown Oklahoma City. (It spans seven miles.) Here, you can rent a kayak, canoe, standup paddleboard, water bike, and several non-motorized watersport equipment. Rafting is also popular. 

This peaceful, slow-flowing river is lined with towering trees. Take in the stunning scenery out on the water via kayak, raft, or canoe. The Tualatin River Water Trail spans 40 miles and features several eateries, parks, and public access points. 

Spanning 444 miles, the Susquehanna River is the longest river on the East Coast of the US. Fishing, kayaking, standup paddleboarding, and canoeing are all popular activities. Additionally, the Pride of Susquehanna offers daily boat tours around Harrisburg, PA. There are also several riverfront hiking and biking trails for visitors to wander. 

Rhode Island's Blackstone River is perfect for paddling. It flows through urban landscapes, small towns, rolling farmland, and lush forests. While you can't swim in the river, you can kayak or canoe. 

The Reedy River runs through downtown Greenville. The river is ideal for both novice and experienced paddlers, which makes it a great spot for families with small children (although swimming isn't recommended). It also offers scenic waterfalls and ample fishing and birding opportunities.

The James River is within easy walking distance from downtown Huron. Here, you can fish right from the shore. (This includes catfish, walleye, crappie, eel, gizzard shad, and dozens more.) Plus, the river is safe for both swimming and boating, so jump right on in. 

The Tenessee River is great for paddling, boating, birding, and biking. Visitors can opt to take a Duck Boat Tour of Chattanooga, which features a boat ride along the river. Couples and grown-up groups will surely appreciate a sunset or dinner sightseeing cruise aboard the Southern Belle Riverboat. 

The Frio River is the perfect place to relax, unwind, and float. As you enjoy the spring-fed waters, take a moment to admire your surroundings, including towering limestone bluffs, beautiful cypress trees, and an array of bird species. The 1,774-acre Garner State Park rests along nearly three miles of the river features 11 miles of scenic hiking trails. You can also swim, kayak, bike, picnic, and fish.

Utah's Virgin River offers stunning scenery (think expansive trees and sandstone cliffs) that you can easily admire from your kayak or canoe. Whitewater rafting is also popular here; however, the drops are quite steep. Tubing is available from May to July, although it's more adventurous than it is relaxing. 

The Winooski River is a popular destination for boating, fishing, and paddling. The slow-moving, tranquil river is also great for beginners thanks to its calm waters.

Virginia's James River (which, yes, is different from the aforementioned James River in South Dakota) spans a whopping 348 miles. Here, guests can go tubing, kayaking, and rafting. The relaxing, three-mile tubing trip lasts anywhere from one to four hours; more information can be found here.

The Columbia River is the largest river within the Pacific Northwest region of the US. Enjoy dozens of miles of waterfront, where you can go windsurfing, kite sailing, kayaking, and boating. 

The Kanawha River flows through downtown Charleston. Here, you can walk one-and-a-half miles along the water towards the city's historic district. While swimming is not recommended, you can go fishing and kayaking. (The river is home to an abundance of several species of bass, as well as catfish, sunfish, sturgeon, and paddlefish -- plus dozens of others.) 

The St. Croix River offers up dozens of miles of clean, clear, water that's perfect for paddling, boating, and fishing. Take a moment to admire the lush foliage and spot wildlife as you canoe or kayak your way down the river. 

The Firehole River begins right below the rim of the Yellowstone Caldera and flows north to Old Faithful. There's also a designated swimming area, where visitors can take a refreshing dip.