Cave Branch Trail

Cave Branch Trail follows the stream corridor of Cave Branch, a small tributary of Tygarts Creek that has been the primary agent carving the Carter Caves complex over the last two million years as the stream cut downward through the Ste. Genevieve and St. Louis Limestone formations, dissolving the soluble rock along fracture lines to create the network of passages that now extends beneath the park in multiple directions. The trail passes directly by the mouths of several caves in the Carter Caves network, including the entrance to X Cave, providing close-up views of the transition zone between surface and subsurface environments where cave-adapted organisms—cave crickets, cave salamanders, and the first inhabitants of the cave—cluster near the threshold of light and dark. The most spectacular surface-level feature on this short trail is the evening emergence of the park's resident bat colony, primarily Indiana bats and big brown bats, from the larger cave entrances at dusk between May and September. Numbers routinely exceed several thousand individuals spiraling upward from the entrance in a continuous dark column for 20 to 30 minutes, then dispersing across the surrounding forest to consume millions of insects through the night. The stream below the cave entrances receives guano-rich water from the caves, creating a nutrient pulse that supports unusually productive aquatic invertebrate communities and the stream salamanders that prey on them.