For many paddlers, Class IV is the secret to longevity in paddling.

For aspiring paddlers, Class IV is the place to test yourself and grow as a kayaker as the fun-to-danger ratio of Class IV is about as high as possible for many boaters.

For the expert, class IV provides a controlled environment to dial in technique and to paddle in a more relaxed setting where you can forget about the mental game and focus purely on the joy of paddling.

For a state with such a vibrant boating scene, Colorado has surprisingly little Class IV kayaking. Think of this list as a progression for an intermediate boater trying to push their limits, or a list of must-do sections for the seasoned paddler. 

Numbers Section of the Arkansas

Not only is this the most famous Class IV section in Colorado, this is one of the most famous sections of Class IV in the country thanks to the rafting scene throughout the valley. Numbers at high water is known for wave trains and big holes (2000+ CFS), while at low water it takes on a boulder garden nature.

What makes the Numbers so fun?

• Lots of rapids
• Virtually no flatwater
• Long season

Eleven Mile Canyon of the South Platte

Not only are the rapids fun and is the scenery beautiful, but the smooth granite boulders and bedrock rapids found in Eleven Mile Canyon are unique for Colorado. To make this run Class IV, make sure to put in below the first rapid, a Class V called Big Bang. 

 
Lower Clear Creek

Lower Clear Creek is likely the most commonly run Class IV run in Colorado. Why? Clear Creek is only 15 minutes to the takeout from Denver. It's an after work hot spot for Front Range kayakers who enjoy the continuous rapids formed from blast rock.

When paddling this section, pay attention for the dam portage (class V+), have some grippy shoes, and make sure to check out the other class IV sections on Clear Creek that are less commonly run, including the Upper Clear Creek Canyon and incredibly fun Lawson to Idaho Springs section.

Cross Mountain Gorge of the Yampa River

Cross Mountain gorge is a deep and continuous canyon with big holes, ledge boofs and surf waves. From the put in, a 5 minute paddle brings you to the mouth of a huge canyon, packed with continuous class IV right up to the takeout.

Take a shuttle back to the top for more laps. Once you know the lines, Cross is a quick run that is worth doing twice (or more!). Be advised that at high water, 4,500+ CFS, Cross is no longer Class IV. 

In fact: during its peak runoff, Cross is one of the burliest big water class V sections in the state.

Upper Animas

While the Upper Animas is pushing Class IV (it has three Class V rapids), it would be wrong to talk about the best whitewater in Colorado without mentioning this stretch.

Continuous and 24 miles long, the Upper Animas offers something truly unique by providing one of the longest, most continuous wilderness runs in the state, if not the country. With the opportunity to run shuttle via train, this section is a true gem.

First timers should:

• Bring a guide
• Have comfortable outfitting
• Be ready for a long yet rewarding day

Honorable mentions:

Gore Canyon

Gore Canyon is not a Class IV run but instead a Class V canyon that deserves respect. With appropriate flows, a good guide, and a few portages, the run quickly becomes IV+ and provides up and coming paddlers an opportunity to push their limits and get a feel for running difficult whitewater. This Colorado mega-classic can be ran late into the fall, making it a go-to option once everything else drops out.

Westwater Canyon

While not in Colorado, the put in for this stretch is just off I-70 over the Colorado/Utah line. Most commonly run as an overnighter, Westwater Canyon is the perfect setting and challenge as a first self support trip, and the deep canyon desert experience makes this a run every Colorado boater needs to put on their bucket list.

What's your favorite class IV in the state that we missed? Comment below.