The first time I did this hike was with my son in 2003. The last time was 4 months ago solo and there were a few other times in between. Plenty of hills but not really long or very steep. Just enough to get a good cardio and be able to enjoy the views and getting a workout and some miles on your feet.
Excellent trail that is mostly single track out and back along Briones reservoir. I've seen plenty of deer on this trail and being along the water many different types of waterfowl and hawks. The trail itself doesn't have any long, tough hills but is just a little up and down roll most of the time. It was one of my favorite little trails around the bay.
Instead of going out and back on the Briones Road Trail, I made a loop by going up to the Mott Peak Trail and the down to the Abrigo Valley Trail. This way I made the hike a bit invigorating and a little more interesting. Total distance was 4.4 miles with elevation 709 feet. It was still a moderate hike. For detail please my recorded track.
Briones is a great place to hike. It gets more traffic now than it ever has. Keep you eyes open. There are a few single tracks that are off the map that you'll enjoy! It was my go to and my training grounds for a decade. Miss it now that I live out of the area...and MT Diablo as well.
I started at the Alhambra Creek Trail. It was mostly shaded. At the end I turned left and followed the Spengler Trail. From Spengler Trail I climbed up onto the Diablo View Trail. This part I had a good view of Mt. Diablo. From there I descended to the parking lot. The loop was short and easy. It took me less than an hour to complete.
Nice hike with some good climbs and views. Grab a map and take a better route than this map shows. No reason not to loop the hike. Briones is such a great place to hike. As long as you have a trail map you can change things up on the fly to a larger degree than almost anywhere in the bay. If you like you can do from 2 -20 miles and still be in the system with a map in your hand...
Very nice foothill hike best done in spring but very good in fall or winter. I've done every inch of Briones multiple times and if you pay attention there is a couple of good single tracks that aren't on any maps... Great place to get the dogs out for a run... Pretty good views up top.
You can do bear Creek Trail without a permit but to do the backside of Briones Res you have to have a EBMUD permit that you can get at their office on the way to San Pablo Res nearby. Cheap and well worth it and is good for several years and allows others to go with you. The loop around the lake is 16 miles I think and is a great hike.