Dublin Neighborhood Hike
This hike isn't anything to write home about, but it does give a nice workout. The terrain is primarily grassland and completely except for a small stretch.
This is a fairly new park evidenced by the nice modern trailhead set at the edge of a newer subdivision. There are restrooms with running water and parking for a few dozen vehicles. The hike starts out as the Calaveras Ridge Regional Trail which goes just above the subdivision, and gently climbs almost a half-mile to a small loop that goes up to the top of Donlon Point for a fine view of Interstate 580 and the tri-valley area. Take the other leg of the .34 mile loop back to Calaveras Ridge, and head north as it gently climbs to its junction with the Donlon Loop Trail about 1.2 miles from the trailhead.
Go right onto Donlon Loop as it heads steeply down Donlon Canyon that has had heavy grazing use. Frogs are frequently heard in the dense riparian forest that lines the creek. Donlon Loop goes down 500' in just less than a mile. The route is a fire road that was nuked by cattle hooves, but it's not too steep to navigate. Follow the signage as the bottom 50 yards of the route go on McBride Lane which is the westernmost tip of a condominium development. The trail goes back into the open space and passes a small drainage retention basin before entering the only forest on this hike.
The pleasant stretch through the forest lasts for only a few hundred yards before the trail begins to aggressively switchback up the steep ridge above Donlon Canyon. This stretch tops out about 2.75 miles in before heading back down to the bottom of Donlon Canyon, and heads up to rejoin Calaveras Ridge. This is the last real uphill of the hike, and you cruise quickly back to the trailhead on a gentle downhill grade.