Rapid 13

Also known as: Range Canyon debris flow rapid, Mile Long entry

Rapid 13 is the upstream end of the Mile Long sequence — the rapid created by the Range Canyon debris-flow outwash entering the Colorado on river-right. The character of the rapid is directly shaped by boulders delivered from the Range Canyon drainage during flash floods. Immediately below Range Canyon Camp, which is the common staging camp for parties scouting Mile Long from the scree-hill perch above. Range Canyon debris-flow outwash is the sediment-science story here: flash floods from Range Canyon deposit boulders and cobbles onto the river, and the Green-Colorado combined discharge works those boulders through the channel creating the Rapid 13 drop. It is a live debris-fan rapid whose character can shift significantly after major Range Canyon flash-flood events.

Difficulty

Class III+ at moderate flows. Builds with runoff and merges into the continuous Mile Long wave train at high water.

How it changes with flow

Low water: Rocky and technical; debris-flow boulders are more exposed.

Medium: Classic read-and-run wave-train drop with a defined line.

High water: Merges into continuous Mile Long wave train; entry committed from R13 through the island at R20.

Scouting

Scouted from the Range Canyon scree-hill perch along with the rest of Mile Long. The entry through Rapid 13 sets up the line through Rapid 14 and Capsize.