Peak 919ft P300
Peak 1,209ft P300

May 24, 2016
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Black Diamond Regional Preserve is located in the Diablo foothills in the north central part of Contra Costa County, immediately south of Antioch. I had been to this park on a previous occasion to visit a CC-listed summit, Rose Hill. There is an even lowlier, unnamed but ranked summit in the eastern part of the park, with another, slightly higher one just outside the park to the south. Today's outing was planned to visit both of these on bike, a 12mi effort that would occupy me for about three hours on a Tuesday morning.

I spent about 90min driving to the junction of Fredrickson Ln and Contra Loma Blvd where the regional preserve trailhead is located. It is surprisingly popular, and there was only one of about 20 spaces left for parking when I arrived just after 9a, mid-week. It took about 35 min to make my way up and over a low ridge into Lone Tree Valley, then up past the old Star Mine quarry site to the top of a spur trail off the Star Mine Trail. The Star Mine was one of the last active coal mines in the area, among the very few coal mining districts in California. The ore was of poor quality and the place was eventually abandoned when richer ore was discovered north in Oregon. The highpoint of Peak 919ft is found about 1/5mi north of where the spur road tops out, leading me to park the bike and hoof it through tall grass to the highpoint, passing along a narrow saddle enroute. Though this would mean another session of sticker removal upon my return, the short hike proved an interesting one, the final climb to the highpoint above the Star Mine involving some easy scrambling and nice views from the rocky summit.

After returning to the bike (and removing a few annoying stickers), I headed west down a single track trail that proved challenging due to its roughness and lack of regular use. This returned me to dry Sand Creek where I turned south to continue towards the second peak. I reached the preserve boundary at the end of Lower Oil Canyon Trail. A sign on a gate here indicated the land on the other side was in a landbank, not exactly private property. After lifting the bike over the gate I followed a series of little-used ranch roads up the mountain, gaing about 600ft over the course of a mile and a half. I came across a second gate about halfway up at the landbank boundary, this one closed by a simply chain clasp sans lock. I startled a deer resting on the road on the other side as I opened the gate to pass through. After more riding, I reached a saddle about 1/6mi SE of the summit at another gate. I parked the bike here and hoofed it cross-country the remaining distance to the summit along thin deer trails, the last half through tall, dry grass. It was a nice view spot to take in the Delta areas to the east, Mt. Diablo to the southwest, rolling hills looking south. Upon returning to the bike I would spent about 20min pulling a far larger quantity of stickers from my socks and shoes which had become painfully inundated with the sharp objects over the short hiking stint. The return was pretty much along the outbound route, with the exception that I bypassed the first summit on the return. The most interesting find was a medium-sized snake I spied basking in the road after nearly running it over. I stopped to encourage it to move out of the road before I continued back to the trailhead. The parking lot was as full as when I had started out earlier, and it took only seconds before the spot I left was occupied by another car. This is one popular trailhead...

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