Explore the most popular hiking trails in Sierra Azul Open Space Preserve with hand-curated trail maps and driving directions as well as detailed reviews and photos from hikers, campers and nature lovers like you.

Only hiked to Priest rock and back on Kennedy because it was very hot, most of the hike is in the open/sun, and I didn’t want to run out of water for my pup and I. Four miles up hill... saw a rattlesnake on the way up and a fox near the top. Lots of sparrows and butterflies along the way. Irises are blooming now. Bring more than one canteen if you’re planning to hike this in the summer!

The parking is limited and not the easiest to back out of if there’s other cars parked.

5/2/2018 This hike is a lot of up and down for a decent view of San Jose. There are not too many switchbacks, so there are a lot of steep but relatively short pitches. Pretty exposed, although there is a decent amount of shade in the beginning and middle for this kind of trail. All the trails are fire road style, and you’re under power lines a lot of the time. You don’t lose the sound of the traffic until the third mile. However, it’s a nice escape from the South Bay, and a good place to let the dogs run as long as you stay mindful of mountain bikers, plentiful here. I made a loop by taking Kennedy Trail back to Priest Rock Trail on the way back, but the original map is easier and shorter. Kennedy follows the ridge line so there is a lot of uphill even on the way back. There are a lot of beautiful wildflowers out and the temperature was perfect even at midday, though the views were hazy. I probably won’t come here much in the summer, especially because there is no swimming in the reservoir. I passed only one mountain biker on a Wednesday midday.

1 month ago

Second time today - same gorgeous hike. First time was right after the trail opened. The newly installed gates at the Hicks road intersection and Bald Mountain parking lot open automatically at 7 am and stay open until after half hour past the sunset.

1 month ago

Hike was pretty easy. When you start your hike and you’re in the woods, there’s this abandoned blue buggy down the hill. Looks super creepy and there was barely anyone on the trail also. Views were alright. I traveled far for this hike but it was eh.

Hiked 4.7.18, right after bay area storm, and pleased that trail was very passable, a little muddy in places, but not much. parking, restrooms were very convenient, trail was very nicely graded, creeks, shades, wildlife (I saw deer, chipmunks, bobcat, and lots of birds), wildflowers, and great views. Very pleased with today's hike.

It’s a nice trail. Gets quite steep at a few spots. That coupled with the total length can make it a hard one. If you’re a regular hiker this should be a nice 4 hour workout. Not too easy but definitely not crazy hard either.
Views up top are nice. Nothing much to see along the way.

1 month ago

Nice cool walk

I really enjoyed hiking this trail. Parking is scarce, find what you can along the side of the road. Went up Limekiln and could hear the streams bubbling. Met more bikers than hikers the day I went. The green gate at the top opens up to a few other trails - but I stayed on this loop. Limekiln provides shaded trails while the Priest Rock side has more open sky. I’d say coming up the other way is more difficult with a steeper incline. All in all, took me under 2 hours to complete including a bit of downhill jogging on the Priest Rock side. Definitely will be coming back to explore the other trails in this area.

2 months ago

IMPORTANT NOTE: the directions take you to the crest of the trail, which is fine if you'd rather go downhill first. if you want to start at the trough as shown in the map, the parking lot you want is the "Sierra Azul open space preserve at Mt. umunhum road parking lot" on Google maps. Great hike, fantastic views of the South Bay.

2 months ago

Not a strenuous hike. But it’s beautiful. On the weekends parking can be a hassle so I’d recommend getting there early. I’d say the hardest part of the hike is the end.

Good up hill workout. Nice rainy day hike with fog. Not many people. There are two entrances along the road. Park at one and take the trail at the top that loops back down. Then walk a bit on the road back to your car where you started.

2 months ago

Spectacular 360 degree view of the Bay Area in top! I could see the Bay Bridge, Lick observatory, and Santa Cruz mountains. The hike itself was moderately easy with lots of shades. I spotted some melting snow near the top. Overall, great hike. Recommend going on weekdays or going early on weekend because parking is limited. I started from the second parking lot for a total of 7.7 miles hike

Not too hard, a little steep at times. Can see SJ, SF, and Oakland from the top!

2 months ago

moderate uphill, not much of a view at the top.

on Mount Umunhum

2 months ago

I’m so glad they opened this preserve up after so many years of being closed. Great hike with decent amount of shade, but there are plenty parts of the hike that are not shaded - so dress in layers would be my advice. Once at the top, it can get quite windy but the views are beautiful. For those who cannot hike the distance, there is a road for cars that will lead you to the top as well. Oh, on a side note, I did come across a tarantula cruising along some rocky path at the very top! So watch your step!

Not the most variety but fantastic views, lots of birds! And because it’s a fire trail, easy to walk with a companion.
My 22 year daughter and I made it to the top but I found it a hard hike. The rolling ridge at the top was a bit daunting for me but worth the trip.
Round trip with a lunch break for us was about 5 1/2 hours.

IMPORTANT FOR DOGS: the last part of ascent (last 500m) does not allow dogs. My wife stood with my dog while I was checking this section. That is a shame because this is the section where you get the best views of San Jose. Definitely hard but not exhausting. Some parts get fairly steep.

Only a small amount 'street' parking; and maybe not strictly legal. Generally easy trail and quiet.

It's nice & quite to hike this place

Hiked 2-10-18. Enjoyed the walk up, noting the beautiful madrones, oak, and manzanita trees. Also got to a see a Bobcat! Trail was nicely shaded with great views of San Jose. I also enjoyed the company of a new friend Peter. Cheers.

3 months ago

Xcellent views limited parking moderate difficulty.

3 months ago

Get there early (8AM) as lots are small and where you park depends on how far you want to hike if your intention is to get to the building. First parking lot - round trip is about 16-17 miles. Second parking lot - 7.5 miles. Third parking lot - a few yards. You can alternatively park in some turnouts, but might be problematic walking on the two lane road.

Trail itself has some nice views. The main trail to Mt Umunhum is very razor thin to have mountain bikers on the trail. Three people can hardly fit side-by-side, so who thought it was a good idea to allow bikers? Also, when they stop, there is hardly any space to pass them.

This has a lot of uphill hiking- it’s not just uphill out and downhill back, so be prepared! Great training!

Beautiful trail and views!!

Excellent trail gradual slope and great view of San Jose valley and surrounding mountain ranges from the top.

4 months ago

Trail is a double track gradually climbing to the summit. There is about a 50/50 mix of trees and unshaded areas. Well maintained and beautiful trail. Took me 4 hours to complete, not including time hanging out at the top. There are bathrooms at the trailhead and at the summit. You can also skip the hike all together and drive all the way to the summit where there is a parking lot. The views at the top are amazing. You can see the entire valley...Mt Diablo, Mt Tam, Mt Hamilton..from Mt Unumhum!

5 months ago

Only about 15 parking space in trail head. You may go weekdays or get there before 8 AM on weekends. The summit has about 56 parking space. The good news is those people who just sight seeing on the summit won't stay long. So you may wait patiently on summit parking lot on weekends to get space. Then hike down and back to summit. The near 360 degree view on summit is gorgerous. You may eat sandwich and rest for half hours on summit and continue your hiking. in general, it's an easy trail, the elevation gain is smooth out over 3.5 miles trail. except for the last section near the umunhum summit, the trail is mostly shady.

Good elevation gain to get you some good exercise. Mostly shaded except at the top. Great views of the reservoir towards the end. Small parking area on roadside at the trail head.

Beautiful hike

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