Arkansas River
The Numbers River Guide
The Numbers is considered Colorado's premier Class IV-V whitewater challenge, featuring a steep gradient of 110 feet per mile through a narrow alpine canyon. Named for the highway mile markers, this 5-mile technical run demands precise boat control through continuous rapids including Twin Pin, Liquid Thunder, Tunnel Slam, and the spectacular Pine View Falls. Surrounded by the majestic Collegiate Peaks, it offers advanced paddlers an adrenaline-pumping experience requiring teamwork and quick decision-making. Minimum age typically 14-15 years.
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Common Questions
What paddlers most often want to know about The Numbers.
How difficult is The Numbers section on the Arkansas River?
The Numbers is Colorado's premier Class IV–V whitewater challenge — a steep, relentless 5-mile section dropping 110 feet per mile through a narrow alpine canyon near Granite. It demands precise boat control, strong paddling fitness, and clear decision-making under pressure.
What class of rapids does The Numbers section of the Arkansas River have?
The Numbers runs Class IV–V with a near-continuous series of demanding rapids named after highway mile markers. Key drops include Twin Pin, Liquid Thunder, Tunnel Slam, and Pine View Falls — all requiring committed, accurate boat handling with minimal recovery between features.
Do I need a permit to run The Numbers on the Arkansas River?
No permit is required to run The Numbers on the Arkansas River. However, the extreme difficulty means it is appropriate only for experienced Class IV–V paddlers.
What is the ideal CFS range for The Numbers on the Arkansas River?
The Numbers runs from roughly 300 to 2,400 CFS. Flows of 400–900 CFS are most common and offer the technical Class IV challenge the section is known for; above 1,200 CFS the rapids push firmly into Class IV+ to V territory.
What is the minimum age or experience requirement for The Numbers?
Most commercial outfitters set a minimum age of 14–15 years for The Numbers, and require prior whitewater experience. Private groups should only attempt this section with at least one paddler experienced in Class IV–V whitewater who has previously scouted or run the section.