The Sunol Regional Park is tucked away near the southern border of Alameda County, just north of Calaveras Reservoir. It is far from any freeway so one gets the feeling of isolation and wilderness that I didn't get at Pleasanton Ridge the previous day. Calaveras Rd leads from Milpitas through the hills and along the reservoir and the park before connecting to Interstate 680 further north. The main entrance to the regional park is side trip on Geary Rd. Just north of Geary Road is Welch Creek Road that provides access to the northern part of the park as well as some exclusive ranch homes several miles east up the road. I had been to Welch Creek Road once before for a hike to Maguire Peaks, but today I was interested in some lesser summits on the south side of the road.
The ride to the start was 25 miles in length, taking me across North San Jose and
Milpitas before climbing into the hills and the scenic ride on Calaveras Rd with
the reservoir off to one side. The road is generally lightly used, making it
ideal for cyclists, but traffic has picked up in recent years as the City of San
Francisco is in the middle of a major 
construction project to rebuild the dam
at the reservoir. The road can be dusty at times and the trucks very large. I spent over
two hours riding to the trailhead off Welch Creek Road. I locked my bike to
the gate found there and started up the old ranch road leading higher into
the park. The 
trailhead and junction signs are an elaborate
arrangement of rock and wood, both sturdy and hard to miss. I followed the road through
the thick shade of oaks growing on the 
south side of the creek canyon, up to
the more open grassy slopes in about half a mile. 
A junction here indicates
Vista Grande to the east in another mile with Flag Hill a slightly shorter distance to
the west. I hiked east up 
a road that follows 
the ridgeline up to
Vista Grande, reaching the viewpoint in about half an hour. There is a lone
oak with a park bench under it located here, with a view looking 
southwest
over the park with the reservoir in the background. There are few signs of civilization
from this vantage. I hiked another quarter mile up the hill to a higher point that
provides a somewhat better view. Here one can see east to a dozen or so 
homes
tucked among the hill slopes at the end of Welch Creek Road. To 
the southeast
are a few even higher summits, though these too are minor points along ridges descending
from Rose Peak further east. To 
the northwest can be seen Maguire Peaks and
further to Sunol Peak and Pleasanton Ridge where I'd spent the previous day. Looking
west, the high ridge upon which sits Mt. Allison and Mission Peak are
prominent.
I descended back down to the junction and then hiked west up to 
Flag Hill,
which is not shown on the 7.5' topo, but is depicted on the
park map.
Flag Hill overlooks the park headquarters which can be seen below to 
the south.
The hike to the summit is only about 15 minutes from the junction. I expected to find a
flag pole with an American flag, but saw neither. About two thirds of a mile northwest of
Flag Hill is the highpoint of this minor ridge, unnamed 
Peak 1,423ft. About
ten minutes additional hiking along road and 
cow trail brought me to its
somewhat 
rocky summit. I took some pictures of the surrounding views
(
N - 
E - 
S - 
W) before starting down. Rather
than follow the road back through the junction, I found a series of cow paths dropping
down off the northeast side of the ridge for a steeper, but much shorter return route. A
couple of 
calves and their mother did not appreciate finding me on their trail,
nor did some 
additional cows that I found back at the start.
I had to clean the thistles and debris from my shoes before getting back on the bike and riding another 25 miles to get home. The rough estimate of 6hrs that I thought the outing would take turned out to be about 6.5hrs - not a bad guess. I was home with time to spare before I had to pick up my daughter from school. A most enjoyable day, to be sure.