If you’ve ever ridden a trail with a section of rocks carefully fitted into the tread, then you’ve probably seen rock armoring. It might look like a bunch of big rocks placed in the trail, but there’s a lot more to it than that.

We use rock armoring in areas where water regularly crosses the trail or where the tread is particularly prone to getting soft and eroding. The goal is to create a durable, rideable surface that can handle both water and bikes while still allowing water to move naturally across the trail.

Think of it as 3D Tetris with big rocks. Each rock is intentionally selected, placed, and fitted together to create a stable surface. Rocks are dug into the trail tread and packed tightly together so they stay put over time and our bike tires can roll smoothly across them.

Gaps need to be tight enough that tires do not get caught, while the finished surface needs to allow water to drain rather than pooling on the trail. The rocks also need to be placed in a way that feels natural in the landscape.

All that takes a lot of skill and attention to detail. You'll see this on the new Trail E at Raging River, where Zander and Matt put in the rock armoring. The result is a great example of how thoughtful trail construction can make a trail more durable long-term while still feeling like it belongs in the landscape.

The completion of Trail E (and Trail C) will mark the end of the final phase of construction at Raging River. Both Trail E and C are on track to be complete and open in mid-October. We’re getting close! 

This work wouldn't be possible without our volunteers, members, donors, and DNR. Thank you for making this project happen!

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