When I go for a hike or climb, I usually am focused on how wonderful it is to be out in nature or I am simply enjoying the freedom of movement. I think most people have similar feelings, and are less concerned for exactly where and how they place their feet, hands, and possessions. However, there is a growing body of literature on how these human actions impact areas of recreation. Theresa Clark and I wanted to add to this literature by studying the differences in vegetation between boulders that had either established climbs or were left alone by climbers. We found that, even in infrequently climbed areas, there was always a clear sign left from climbing: reduced vegetation biodiversity. Interestingly, in these less frequently climbed areas, we also found signs of some positive impacts of climbing on biodiversity: a number of species were only found on climbed boulders. While increased users would probably bring negative impacts to our study sites, being careful with how you climb and clean climbing holds would probably help biodiversity a lot. When possible, simply try to avoid patches of vegetation or soil, no matter how small, and maybe don’t establish new climbs on wet, mossy rock that probably won’t make for a great climb anyway. Check out the study in Biological Conservation.