The beautiful but sometimes hard-to-follow Fry Creek Trail circles the head of a densely wooded drainage on Palomar Mountain, reminding anyone on it (at least at this time of year) that vivid autumn colors really do exist in San Diego County.
Drive up Palomar Mountain on South Grade Road, then turn left on the road to Palomar Observatory. Proceed 2.7 miles north to where (about 2 miles shy of the observatory) you'll spot Fry Creek Campground on the left. Parking outside the seasonally closed campground requires a National Forest Adventure Pass ($5 daily, $30 yearly), which is widely available at ranger stations, backcountry stores, and recreational outlets throughout the county.
Just inside the campground gate you should find the start of the 1.5-mile-long Fry Creek Trail. You wind up along an oak-shaded slope north of the Fry Creek ravine, cross a dirt road, and continue on to a grove of planted "Penny Pines." The pines in this case are Coulter pines, having long, gray needles and massive cones. The oaks are of two main types: live oaks that retain their leathery leaves the year round and black oaks, which are representatives of the only deciduous oak in San Diego County. In most years, the black oaks at this elevation are ablaze with color in late October and early November. Listen for the sporadic pitter-patter of falling acorns.
After you reach the Penny Pines, don't take the road to the east (a shortcut to the campground) if you want to complete the whole trail. Instead, find and follow the continuation of the Fry Creek Trail, which angles down the slope south of the creek. You thread your way amid closely spaced incense-cedar, white fir, and live oak tree trunks. Very few black oaks and no Coulter pines grow here -- they seem to prefer the sunnier slopes on the other (north) side of the creek.