There’s not too much to worry about here. However, after a few more decades of humanity doing little to arrest climate change, dangerous arthropods will probably become commonplace in Yellowstone. For now though, there are just a few things to keep in mind.
First, Yellowstone is not known to harbor populations of either black widow or brown recluse spiders. Yet we have black widows around our home, just a few miles from the park. So it is likely that there are black widows in the lowest elevations of Yellowstone, mainly in the lower Black Canyon of the Yellowstone River, above the town of Gardiner. Old timers, by the way, tell me that black widows are relatively new to this region, either having arrived here due to human travel or climate warming or some combination of both. Also, note that with our annual influx of tourists from warmer climates, it would not be impossible for poisonous spiders or for that matter even scorpions to “hitch” a ride into the Greater Yellowstone area and survive, at least for a while. So don’t assume that Yellowstone’s altitude automatically protects you from “creepy crawlies”. It does not. But again, especially in the higher terrain, stings and bites are a minimal concern.
On our guided Yellowstone backpack treks we are usually in relatively high country, so aside from the common annoyance of mosquitoes and horse-flies, bee-stings are our primary concern. Our guides carry “epi-pens” in case of an anaphylactic reaction, but fortunately, we’ve never had to use one. And especially in the mid-summer wildflower season try not to dress, for example, in bright yellow and pink clothing so that bees won’t view you as a giant walking wildflower! Also, watch where you put your hands and watch where you sit. The last thing you want to do is to sit on a yellow-jacket nest, and they do nest in the ground. Common sense. Please use it.
