We put hundreds of hours a year on the Snake River and it is all rock, the softest part on it is gravel and sandstone, the rest is granite and lava rock. We have learned to read the river ahead and trim up often, but hitting rocks is more common than not.
The rock guard holds up well, but we do check and tighten the bolts since a half dozen man sized rocks a trip can make them loose, not often, but it can loosen and then be prone to shear.
Coupled with our 1/4" steel skeg, the rock guard extends prop life considerably. Any motor heading for this river with miles in mind has a rock guard or buys a prop a weekend.
The Duck Commander hunted with us awhile back and had his taste of this western river, the toughest mud motor water you can imagine. Keep your rock guard on and keep those bolts tight.
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