The nature center is a good place to start before heading out to explore the 6,347-acre Santa Ysabel Preserve. There are interactive exhibits, maps, info on ranger-led hikes and astronomy lectures, restrooms, and a water refilling station. This valley looks pretty much the way the backcountry appeared a century ago, with sweeping meadows surrounded by oak-studded hillsides. The San Dieguito River (Santa Ysabel Creek) emerges from Volcan Mountain here and winds its way 65 miles to San Dieguito Lagoon at Del Mar along the Coast to Crest Trail. A 7-mile trail follows the river for the first mile, from Farmer Road in Julian to the East Entrance of Santa Ysabel Preserve. Legacy oak trees shade the trail, there are spectacular views along the way, and picnic tables abound. The trail is best explored in the fall.