The Dublin Hills Regional Park is a pretty little hidden gem surrounded by highways and some new development. The trailhead/parking area is one of the more modern ones I've seen. It's easily accessible and has plenty of parking, so it's worth a visit.
Location: To reach Dublin Hills: From I-680 southbound in San Ramon, take Exit 31, the San Ramon Valley Blvd. exit. Turn left on San Ramon Valley Blvd. San Ramon Valley Blvd. becomes San Ramon Road. Continue south to Dublin Blvd. and turn right (west). Continue west on Dublin Blvd. for two miles. The staging area is on the right. From I-680 northbound in Dublin, take exit 31, the Alcosta Blvd. exit. Turn left on Alcosta, and left again on San Ramon Road. Continue south to Dublin Blvd. and turn right (west). Continue west on Dublin Blvd. for two miles. The staging area is on the right. From I-580 eastbound or westbound, take exit 44A, the San Ramon Road/Foothil Road exit, and turn north on San Ramon Road/Foothill Road to Dublin Blvd. Turn west on Dublin Blvd. and drive for about two miles. The staging area is on the right.
Mileage: 4.07 miles
Ascent: 1553 feet
Descent: 1591 feet
Start out at the Donlon Point Staging Area. Lots of parking here, and bathrooms.
Most of this hike is exposed, with a little canopy area to rest under at about the half way point. However, you'll probably see some hawks hunting, and you'll certainly see cows. The trail is dotted with their reminders, so step carefully. You'll start out with a short (.13 miles) climb to the Caleveras Ridge Trail. Take a right at the top, on to the trail. As you climb, you'll see the development being built on your left.
There was construction going on during the hike, so this neighborhood is still being expanded. Keep right at marker 2, on to the Calaveras Ridge Trail. Keep left past markers 3 and 4. To your right is the short Donlon Point loop if you want to take it. Otherwise, follow the Calaveras Ridge Regional Trail to marker 5. On the Calaveras Ridge Trail, you'll have nice views of Dublin and Pleasanton across the valley.
The wind coming up from the valley was powerful, but it was wonderful watching the hawks ride this current.
At marker 5, take a right to the Donlon Loop Trail. You'll see the residents hanging out at the local watering hole, just chewing the cud.
At marker 6, you can go right or straight to complete this loop, I went straight. You'll soon come across another split. If you continue straight, you'll get on to the Martin Canyon Creek Trail, but go Right, on to the Donlon Loop Trail. This starts a nice little climb that will bring some air in to your lungs. The vista will open up as you climb, and you'll see more of Dublin and Pleasanton below you. At the top, you'll take a sharp right and descend on to a single track trail.
Go through a gate, and soon you'll descend in to a nice little canyon full of Bay trees and Oaks.
This is a nice place to rest in the shade and enjoy the beauty. There is a stream bed here, but it was bone dry, not good for this time of year. The trail crosses on to a residential street for a short detour, but it's well marked, and you'll have no problems reconnecting to the trail.
After you reconnect with the trail, you'll enjoy a little more canopy and foliage.
There is a little bit of a climb as you hike back to the start of the loop. The trail was heavily rutted here, so step carefully so you don't twist an ankle. When the ground is wet, the cows make deep impressions in the trail, and when it dries out, these impressions leave deep holes that are hazards for hikers and runners.
These hikers were enjoying the view from the Calaveras Ridge Trail.
Continue on the loop back to marker 6. Take a left there, and at marker 5, and continue back to the parking area.
Enjoy your hike, and be safe.