The Story of The Numbers

Located about ten miles north of Buena Vista, Colorado, The Numbers section begins just below the confluence of Lake Creek, where Twin Lakes Reservoir adds recreational water to the Arkansas River to ensure this section remains optimal longer than any other Class IV rafting trip the state.

The six major rapids in this section are creativley named – Numbers 1 through 6 – in downstream order. The sequence marks one of the most famous sets of continuous whitewater drops in North America.

The put in rests at 8,640 feet of elevation and descends through granite canyons carved by meltwater from the Sawatch Mountain Range. The rocks here are ancient, formed over a billion years ago. Their tight channels and smooth ledges shape the signature hydraulics that make The Numbers technical and thrilling.

River Conditions & Seasonality

Flowing between May and early September, The Numbers offers Colorado’s longest Class IV rafting season. In May and June, snowmelt from the surrounding peaks pushes flows between 1,200 and 2,500 CFS, forming crushing waves, big holes, and strong eddies.

From mid-July through August 15th, water released from Twin Lakes and Turquoise Lake Reservoirs keeps the river running strong, averaging 700–1,200 CFS even after natural snowmelt subsides. These managed flows make The Numbers not only thrilling but remarkably reliable, a rare feature for a high adventure run.

By August 15th, the river drops to a 350 CFS base flow, offering a more technical experience that requires tactical maneuvering around large boulders to slide through tight shoots and drops.

Check current and historical water levels on the USGS Arkansas River Gauge at Numbers.

Trip Details

The Numbers covers 5.98 miles of steep-gradient whitewater, dropping an average of 71 feet per mile through tight chutes, stair-step drops, and sharp turns. The put-in is accessed via Colorado Highway 124 (County Road 371), which follows the east bank of the river and offers BLM camping spots and scenic overlooks along the way.

Trips put in at The Numbers Recreation Site and takes out at Railroad Bridge, where the canyon widens and the gradient eases. Continuous Class II and III waves connect the six major Class IV rapids; Number 1, Number 2, Number 3, Number 4, Number 5, and Number 6  for nearly nonstop action with short recovery pools between each.

Expect roughly 1.5 hours on the water for the half-day trip, or extend your adventure with the full-day option, which continues into the Narrows section for another six miles of scenic Class II–III whitewater. The full-day trip includes a riverside bakery-fresh lunch near the railroad bridge takeout for the half day trip and continues another 7 miles of consistent class II and III whitewater to the town of Buena Vista, totaling about 4 hours on the water and 5 hours 45 minutes round trip.

Trips meet daily at our Buena Vista outpost on Hwy 285, with multiple start times available:
½-Day Trips: 8:15, 9:15 am, 11:15 am, and 1:15 pm

Full Day Trips: 9:15 am

2 Day & 3 Day Expeditions: Meet at 9:30 am on Tuesdays and Mondays respectively.