Yes, it's all over the place. Lots of petrified wood too, so you'll come across that as well. Just ask the outfitter for the groover, but it should be included with the canoe. Definitely a "floating" river, meaning you'll not really need to row much at all.
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seeking to balance risk and reward
Audaces fortuna iuvat...fortune favors the bold
Practice methodical caution...Les Stroud