To take this 80-mile loop, take California Highway 76 east from Interstate 15 to County Highway S6. Turn left (north) to Palomar Observatory. Return by going partway back down S6 and turning left (southeast) on County Highway S7, which leads to overlooks of Lake Henshaw before descending back to Highway 76. Take 76 west to return to I-15.
I chose this drive because I was curious about the region and the observatory, which is owned by the California Institute of Technology in Pasadena and renowned for its 200-inch Hale telescope. In the past, I had bicycled down the county's coastline and explored Anza-Borrego Desert State Park on the county's eastern edge. What, I wondered, lies between these tourist destinations?
What my partner, Wesla, and I found on a weekend in early June was diverse and sometimes striking scenery. There was Cleveland National Forest, with its scenic overlooks and pine-covered mountains. There were citrus orchards, pastures and produce farms. Some stretches of boulder-studded hills resembled the Italian countryside.
Palomar Observatory, with its minimal, outdated exhibits, disappointed me. (There are plans to update the displays in the next few months.) Its pleasant grounds, which had a shady picnic area, offered no overlook, despite the 5,550-foot elevation. But the winding, 11-mile drive up to the site, dubbed the Highway to the Stars, was first-rate.
Expect company on S6, a snaking road that motorcyclists also favor. We found nearly 50 of them parked outside Mother's Kitchen restaurant, a vegetarian cafe near the S6-S7 junction, where we had a fine lunch (veggie chili for me, faux-meat tacos for Wesla).
Looming over Highway 76, about five miles east of I-15, you'll find the giant Pala Casino complex, which is part of the Pala Indian Reservation. It is scheduled to become the Pala Casino Resort and Spa in August when it opens a 507-room hotel and a 10,000-square-foot spa.
Otherwise, the loop has a dearth of roadside services. Check your car, fill it with gas and get some drinking water before heading out.
Before starting our drive, we had overnighted at the new, two-room Blue Heron Farm Bed & Breakfast on a 20-acre organic farm in rural Fallbrook, about 10 miles off I-15. Our Peacock Suite in the rambling Mediterranean-style farmhouse was spacious, with two balconies overlooking the hillside.
Our eggs-and-waffles breakfast included strawberries, honey, kumquat marmalade and lemon verbena tea — all from the farm — plus grapefruit picked that morning.
Blue Heron Farm Bed & Breakfast, 5910 Camino Baja Cerro, Fallbrook, CA 92028; (760) 439-6466, http://www.blueheronfarmbandb.com . Doubles from $150.
Mother's Kitchen, Junction of S6 and S7, P.O. Box 100, Palomar Mountain, CA 92060; (760) 742-4233. Entrees $3.95-$6.95.