Mile 0.0: Pick up the preserve brochure from a display at the (unstaffed) visitor center. Start on a paved road to the right of that building, and begin walking slightly uphill. Mile 0.1: Junction. Bear right and continue an easy ascent, with a sloping hillside on the right, and coast live oak, Monterey pine, and California bay to the left. Mile 0.3: Junction. Turn right onto Round Top Loop Trail. The path steps into a forest of Monterey pine. Mile 0.3: Junction. The Bay Area Ridge Trail segment heads downhill toward Huckleberry Preserve, on the right. Continue straight on Round Top Loop Trail. The path bisects a spooky grove of eucalyptus (some dying, some already dead), then climbs into grassland. Mile 0.6: Crest near the preserve boundary. A fire break veers right, but stay to the left. There are sweeping views to Mount Diablo on clear days, and on one December hike I saw east all the way to the snow-topped Sierra. Round Top Loop Trail descends gently. Mile 0.8: Junction and stop #4 on the self-guided volcanic tour. Walk straight toward the post and protective fence for a bird's eye view of the largest Sibley labyrinth. Then walk back toward the junction, turn left, and descend to the labyrinth. Mile 0.9: Quarry pit and labyrinth. The area becomes a seasonal wetland after winter rains. When ready, walk back to the previous junction. Mile 1.0: Junction again. This time continue straight on Round Top Loop Trail, which descends just a bit. Mile 1.3: Junction. Continue straight on Volcanic Trail. Forests of eucalyptus downslope to the left fail to block views north to Vollmer Peak. Mile 1.5: Junction. Bear right, then continue straight as another path crosses this one (quite a few paths trace through the grass and cow paths contribute to the confusion through here). Mile 1.6: Second labyrinth, this one heart-shaped. Retrace your steps back to the junction with Volcanic Trail. Mile 2.0: Junction. Bear right onto Round Top Loop Trail. Coyote brush lines the trail as it sweeps around the north face of Round Top. Mile 2.3: Junction with paved road and a handful of paths. Stay to the right on the trail, then when the paths split, stay right again. This little path descends, crowded by eucalyptus, blackberry, and coyote brush. You'll reach a small interpretive site, where one placard highlights the flora and fauna of the preserve, and another points out local landmarks. From here, the remainder of the path is paved. Miles 2.6: Back at the trailhead.
