Looking for that true colorado rocky mountain high the numbers section of the arkansas river got its name in the late 1800s by local miners who viewed the rapids as non navigable landmarks they were so intimidated that they just numbered the rapids instead of naming them if you are an experienced rafter looking to take it to the next level or an adventurous beginner up for a new challenge the numbers rafting trips are some of the best arkansas river white water rafting trips around