Tunnel Vision
Old Tunnel State Park sits on a brush-covered limestone ridge that divides the watersheds of the Guadalupe and Pedernales rivers, about halfway between Fredericksburg and Comfort. With only 16 acres and three picnic tables, the park is the smallest in the state system. Every evening from May through October, visitors perch on low wooden bleachers to watch 3 million Mexican free-tailed and cave myotis bats swarm out of the abandoned railroad tunnel, spiraling into the dusk above hills that march toward the horizon.
Near the bleachers, an unpaved trail descends a hillside to the tunnel entrance, which looks like an ancient crypt in the limestone cliff. A sign warns visitors to stay out of the tunnel, but given the bat guano piled in the damp darkness,
