Only one official trail — the Pacific Crest Trail — runs through the Cascade-Siskiyou National Monument, but old dirt roads that are off-limits to vehicles place miles of backcountry within reach of a hearty hiker. A one-mile detour from the PCT leads north to Porcupine Mountain, an old lava flow that oozes chunks of black basalt from the thin soil along its edges.

Only one official trail — the Pacific Crest Trail — runs through the Cascade-Siskiyou National Monument, but old dirt roads that are off-limits to vehicles place miles of backcountry within reach of a hearty hiker. A one-mile detour from the PCT leads north to Porcupine Mountain, an old lava flow that oozes chunks of black basalt from the thin soil along its edges.

Dry, cool, fall weather is best for hiking roads that can be muddy in spring and hot in summer. Fall is also the safest time to traipse over Porcupine Mountain's fragile flanks, held in place with a sprinkling of dried wildflowers and bunch grasses.

You can park a mile from the summit and create a 2.75-mile loop with the PCT or begin at the PCT trailhead near Pilot Rock for a six-mile out-and-back hike that starts in old forest, where flickers and pileated woodpeckers make their distinctive calls.

Take Mount Ashland Exit 6 off I-5 and travel south 1.8 miles. Turn left on bumpy Pilot Rock Road, 40-2E-33. Make uphill choices and honor No Trespassing signs at private roads as you continue 2.2 miles to a gravel pit. For the six-mile hike, veer right for .8 miles to the end of the road, and start east on the PCT. For the 2.75-mile loop, continue straight (east) at the gravel pit on an unmarked continuation of 40-2E-33, a rough four-wheel drive track. Curve right at a fork in .5 miles. Park at a pass near a black gate (1.7 miles).

The longer route features a panoramic view of the Shasta Valley at one mile. This view captures the Klamath-Siskiyou range as it bumps into the southern Cascades. Double-humped Black Butte, a 6,350-foot peak, stands dwarfed between the Eddys to the west and Mount Shasta to the east. Shield volcanoes, including the Whaleback and Goosenest, line up to the north of Mount Shasta.

At two miles, the trail crosses a gated road and the easternmost PCT access point on the monument's west side (5,160 feet). You can drive to this point but must proceed on foot from here.

Leave the PCT and turn right (east) on a deeply rutted road that ascends sharply. Look for ripe elderberries here. The PCT braids back and forth across this road (40-2E-30) throughout much of the monument. At .5 miles, switchback left up an even steeper road. When the road ends in a few minutes, turn north (the only logical direction) and follow a faint path past a few juniper trees to a small knoll surrounded by brightly colored oaks, incense cedar and Douglas fir. Look for a way trail through a narrow woodland and continue north toward open, sloping ground.

Pay attention to the point where you leave the woods and start climbing the nearly treeless hillside. Pilot Rock stands behind you and Mount McLoughlin rises to your north as you aim directly toward an exposed ribbon of basalt that's about 15 feet tall. Scale the wall carefully, looking for footholds in the rock.

The 5,300-foot summit (Lat: 42°02'47.87"N Long: 122°32'39.55"W) is a short, easy walk through a jumble of juniper, mountain mahogany, knee-high manzanita and serviceberry. Perhaps porcupines would like Porcupine Mountain, but the landscape looks more like rattlesnake territory. From this perch, you can look north to the ridgeline that connects the Siskiyous to the Cascades and to dead-end ridges that point toward the Klamath River. You can pick out Soda Mountain to the east by its communication towers and Mount Ashland to the west by its globe-shaped weather station.

On your return, loop to the PCT by turning left (west) on the crest road, then right on the PCT in .2 miles. A final mile-long stretch of trail to the black gate starts with fall-bright shrubs and classic views of Mount Shasta and finishes in deep woods.

Pick up a map of the Cascade-Siskiyou National Monument at the BLM office at 3040 Biddle Road, Medford.

Mary Beth Lee is an Ashland writer. Reach her at gentlejourneys@ashlandhome.net.