Old Guano Trail

Old Guano Trail is a point-to-point walk of about 4.2 miles one way, from beside Carlsbad Cavern’s Natural Entrance to the White’s City campground. It follows the old haul road down the escarpment, with mining remains and open desert views along the way. The NPS page lists 3.7 miles one way; the mapped entrance-to-campground line measures 4.23. A published out-and-back figure is 7.5 miles, but retracing this mapped line is about 8.5 miles. I’d plan around the longer map distance. The park estimates two hours one way; allow about 2–2½ hours for this line.

This is easiest if you have a ride waiting at White’s City. The NPS trail page does not describe a shuttle or return service. Without a pickup, you’ll have to retrace the route and climb back up the escarpment.

The trail follows the road used to haul guano from Carlsbad Cavern in the early 1900s. About a mile from the entrance, the NPS says you can see mining ruins and debris. The route also passes stone culverts and rock quarries. Guano mining began here in 1903; about 120,000 tons were removed by 1911 for fertilizer used in California citrus groves. That history gives this walk a more unusual payoff than a simple descent through desert.

The NPS describes the first 2.3 miles as a gradual descent, followed by a steep final stretch; its page says that last 1.4 miles loses 572 feet. The mapped line is longer than the published total, so treat those mile markers as approximate. The elevation profile for the mapped route shows about 700 feet of total descent. If you turn around at White’s City, you climb that back on the return.

This is a backcountry desert walk. There is no reliable water source along the route, and cell reception is limited. The NPS warns of summer heat above 100°F, winter ice or snow, lightning and flash floods. The route is closed near the Natural Entrance during Bat Flight Programs, and pets are not allowed on park trails. Check the park’s access information before setting out, especially if your plans depend on reaching the entrance during an evening program.