Region
Highlights
- "The Cube", a 5-story concrete former Cold War radar installation on Mt Um's summit
- Extensive views of San Jose and all of the most prominent summits of the Bay Area on a clear day -- Mt Tamalpais, Mt Diablo, and Mt Hamilton
Routes
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
8 summits • 8.5 mi • 1,160 ft gain • 2 hr 12 min • Class 1
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
1 summit • 17.0 mi • 2,585 ft gain • 5 hr 47 min
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
1 summit • 10.3 mi • 3,166 ft gain • 4 hr 21 min
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
1 summit • 10.4 mi • 1,075 ft gain • 6 hr 22 min
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
1 summit • 8.1 mi • 1,016 ft gain • 2 hr 33 min
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
1 summit • 9.4 mi • 1,064 ft gain • 3 hr 49 min
/-121.89888420105,37.1602052084901,11,0.00,0.00/320x240@2x?access_token=pk.eyJ1IjoicGVha2VyeSIsImEiOiJjampra3Z0bnAxeTVnM3FteHlybHY3b2p1In0.7a5dEa5-995VUv8ceHHNmw)
1 summit • 9.8 mi • 968 ft gain • 3 hr 4 min
Latest summits
"Bald and Mount U out of the Bald Mountain PA. A little cool and breezy but still shorts weather for this east coast resident. A speedy saunter up Mt U provide all the warmth I needed especially in the shady sections of the trail. Some knucklehead, most likely a car ascender, left an empty disposable water bottle on the west summit so I packed it out it. I thought I left “stupid” back in NY state but apparently it’s running loose from coast to coast. Today was the busiest I’ve seen the trail/summit on a week day, I’m assuming it’s do to coming food fest this coming Thursday, everyone is home from work and school.
Bald mountain was a nice leg stretcher after running down Mt U.
" — Nimblefoot • Nov 20, 2023
"Original plan was to red line the Kennedy trail up to the Bay Area Ridge trail then head toward Mount U but the small parking area was already full. The hazards of sleeping in and getting a late start. Plan B became head over to Mount U road for a fast saunter up to the summit on the nicely graded and shady trail then saunter over to Bald Mtn after getting back to the car. This time I was able to hike the final 0.2 miles of the trail and visit the east summit. Last time the gate was closed as the trail was deemed unsafe so I had to head over to the parking lot then up to the west summit. There was construction on the Cube building going on with fences up so I couldn’t access the east summit.
Nice view from Mt Hamilton to Mt Diablo but SF and Mt Tam were socked in.
Bald mtn was an easy stroll out to a grassy hillock.
" — Nimblefoot • Jul 24, 2023

"Despite the recent rain and high winds in the Bay Area, the trail is in very good condition: no downed trees, no mudslides, and only 2-3 spots on the Barlow Road with standing mud/water (which were easily avoided)." — michaelwin • Jan 12, 2023

"This hike goes for 7 miles. We saw some car wrecks, some bridges, and crossed a junction. The trail passed through a forest for most of the hike. We went to Guadalupe Creek Overlook as well. There is no benchmark on the summit" — lc444 • Sep 7, 2022
"An easy twofer from Bald mountain PA. Mount U first on a nice wide trail with plenty of switchbacks. Unfortunately the final stretch of trail, access road, building and true summit were closed do to work being done on the building. Back to the PA and onto an easy stroll up to the little knob of Bald. Great view that was reduced a bit with the smog/haze from the toasty temps." — Nimblefoot • Jul 30, 2021

"Hot day in San Jose in the 90s. Dropped a car at the Umunhum summit around 11am, and shuttled the four of us down to Jacques parking lot. Lot was full, but we were able to park on a nearby street.
Headed up the trail from there. Mixed shade and full sun exposure areas. Was much less hot up there compared to on the valley floor, and managed to get by without a sunburn.
Took a detour for the Bald Mountain trail which was mostly flat, only about 2 miles and overall pretty relaxing.
Apart from the lack of any breaks, our pace was fairly leisurely. We passed quite a few people (maybe 50 total). About half wearing masks for COVID. Views were better than expected. Great hike.
We reached the Umunhum summit 4.5 hours after starting. 10.8 miles total, 2600ft elevation gain." — HolyBejeesus • May 24, 2020

"Parked at the Bald Mountain parking lot. Got there about 10ish. Only a few other cars in the lot with one group already returning. Quickly packed up and hit the trail head across the road. Started with no wind, mostly clear skies and about 49 degrees. Had the trail to myself to start but was met by a group of about seven deer that were grazing on the trail. They had no fear of me and when I got too close they would simple trot a few feet away and continue grazing. After a bit they left the trail and melted back into the trees. The trail is great. A gentle grade the whole way, did not use my trekking poles at all. Total worth making the very short trip off the main trail to the Guadalupe Creek overlook. Amazing views at several points along the trail. Only saw a few others on the trail on the way up. Unfortunately one group was very loud, no music, just talking. I do not go out on the trails to clearly hear others conversations from several hundred yards away. This would also be an issue on the return trip as the trail got busy. The summit was amazing with 360 views. Wind at the summit was about 20-25mph. Not crowded but I would imagine that this area is packed on weekends. Returned..." — Mtstalker • Jan 3, 2020
"Landed at SJC at 9 and was on the trail by 10. The Open Space space folks did a great job restoring this area and building trails and facilities at the summit. Really enjoyable quick hike with a lot of history." — edg • Jan 19, 2019

"Midpeninsula Regional Open Space District
Sierra Azul Open Space Preserve
Mt. Umunhum Trail
10.43 Miles
Ascent 1,075 ft (-1,075)
12 Geocache(s)
1 BenchMark
1 WarkMark
2 Peaks
6:22 Total Time" — jminkema • Mar 11, 2018

"Nice trail - easy to hike. The peak is immaculate, seriously clean (felt bad for dropping chip crumbs). The trail to the radar tower is closed, but you can still get to the peak on the road and up a few flights of stairs. " — colleenmarie512 • Dec 2, 2017