Zapata Falls flows into a narrow crevasse south of Great Sand Dunes National Park. NPS/Patrick Myers. This popular short hike is located on BLM (US Bureau of Land Management) land south of the national park, off of Highway 150. It is a good option for summer afternoons when sand surface temperatures are high. Simply driving to the trailhead provides an excellent view of the entire dunefield and San Luis Valley. However, the hike to the falls requires wading over slippery rocks into a rock crevasse.