Sinkhole Trail

Sinkhole Trail is a 1.0-mile point-to-point connector from Heritage Trail to Echo River Springs Trail. Allow about 45 minutes one way; walking it back makes a two-mile outing. A signed spur leads to Mammoth Dome Sink, a wooded surface hollow tied to Mammoth Cave's underground geology. The route is short, but the rocky, rooted ridge and steep spur make it more demanding than a flat stroll.

From the visitor center, cross the footbridge behind it toward the lodge, then follow the Heritage Trail boardwalk to the signed northern junction. At the River Valley Trail junction, follow signs toward White's Cave and Echo River; at the White's Cave Trail junction, keep right for Sinkhole Trail. The route ends on Echo River Spring Trail, so retrace Sinkhole Trail or continue on another trail if you need to return. The separate paved Echo River Spring loop adds 0.7 mile. Dogs may use park surface trails on a leash no longer than six feet.

The first roughly 0.15 mile is smooth, level dirt. Then the tread follows a narrow ridge with rocks and roots, a steep drop on one side and a bank on the other. After a short level break, take the 150-foot spur about 0.4 mile from the Heritage end down into the sink; it is steep enough that you have to climb back out. A shallow valley gives you a gentler middle stretch. The final section is rockier and descends toward Echo River Spring, with several brief pitches reported as steep as 30 percent.

Mammoth Dome Sink is more like a wooded gully than a dramatic open chasm. A wayside panel explains the cave connection. The underground Mammoth Dome is a vertical shaft more than 190 feet tall; water drains down cracks that cross the area's limestone layers. For a photo, include the exposed limestone ledges with the leaf-covered hollow to show what the sink actually looks like.