04/28/2026
No need to be stacking them on land either. You're not Sir John Franklin.
That cute rock stack by the creek just killed a bunch of mosquito killers.
Dragonflies spend most of their lives underwater, sometimes up to five years, clinging to rocks while they grow.
A single dragonfly larva eats hundreds of mosquito larvae before it ever flies.
But dragonflies are just one species. The rocks in a healthy stream are also covering caddisfly larvae, mayflies, stoneflies, water beetles, salamander egg clutches, and the freshwater snails that fish depend on.
Eastern Hellbenders, an endangered giant salamander species, lay their eggs specifically under flat stream rocks. Moving the rock kills the clutch.
When you pull a wet rock out of the water and stack it on the bank, everything clinging to that rock dies. They desiccate within minutes in the sun.
A single rock pile is dozens of small lives lost. Most stream cairns are stacks of fifteen to twenty rocks.
If you see stacked rocks at a creek, knock them over. The stream rebuilds itself faster when rocks are scattered the way water put them.
Leave no trace isn't an aesthetic preference. It's real habitat protection.
