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Sierra Azul Open Space Preserve
4.7 ★★★★★ 733 Google reviews · Running trail in San Jose, California · Hours vary
Runner's snapshot
- Surface
- Mixed
- Distance
- 26 mi
- Shape
- Not reported
- Shade
- Tree cover
- Access
- Not reported
Confirmed from Sierra Azul Open Space Preserve's own listing, the park or land manager's website, and runner reviews. Blank cells mean we could not verify that fact — we would rather say "not reported" than invent one. There is no Easy / Moderate / Hard rating on this page on purpose: a one-word difficulty score tells you nothing about whether a trail suits your run. Surface, distance, shade and hours do.
18,000-acre wilderness area in mountainous terrain with hiking trails, wildlife & valley views.
What runners say about Sierra Azul Open Space Preserve
“Beautiful vista of the mountains, up close and personal 👌🏽 pro tip: go when the clouds are heavy, you will be walking in them.”
“They have a well maintained park that has perfect trails for hiking when it's really hot out since it is shady.”
Trails around Mt Umunhum have been a great pleasure. The views from the top are wonderful. One can drive all they way up to the top - a real blessing for our aging parents. The peak gets a smattering of snow in the winter. The trails have ample shade - which is helpful in the summer time.
Sierra Azul Open Space Preserve Standing on the top of the mountain and looking down below, you feel like you can see all at a glance. Excellent opportunity for exercise PARKING LOT: The parking lot at the top of Sierra Azul Parking Lot At Mount Umunhum Summit Area is quite large and is also one of the best places for…
My special healing trail for many years now .It is just beautiful ! Be aware there are monutain lions in this area and recently I have had encounter with one on the trail - October 19 2025 . It was bit scarry because I realized this beautiful cat follow me at dusk . So just be aware and avoid dusk .
Unlike most mountain top radio sites, this one has paved roads and a parking lot at the top. You can reach it in an ordinary passenger car - no 4WD needed. The large concrete building is one of the old SAGE RADAR sites from the cold war. I sure hope to see it as a museum someday since it is historically significant.
Trail conditions & character
“Beautiful vista of the mountains, up close and personal 👌🏽 pro tip: go when the clouds are heavy, you will be walking in them.”
“Parking at the top is good and a short paved climb to the observation deck overlooking San Jose and the surrounding hills.”
“Parking at the top is good and a short paved climb to the observation deck overlooking San Jose and the surrounding hills.”
“Parking at the top is good and a short paved climb to the observation deck overlooking San Jose and the surrounding hills.”
“They have a well maintained park that has perfect trails for hiking when it's really hot out since it is shady.”
“other You can ride bikes on the trail, but you cannot walk dogs.”
“bathroom Located in the parking lot at the top of the mountain, hand washing is not allowed.”
Plan your run at Sierra Azul Open Space Preserve
The practical stuff
- AccessHours vary — hours are not posted for this trail, so check before an early or late run
- SurfaceMixed — more than one surface along the route, so check the segment you plan to run
- Distance26 mi as reported — check whether that is one way or a round trip before you commit. Long enough for a real long run.
- ShadeRunners describe real tree cover here — it makes a summer afternoon workable
- At the trailheadparking, restrooms, water — reported by runners
- DogsWelcome, per reviewers. Leash rules vary by park — the trailhead sign is the authority.
- Stroller / wheelchairReported as smooth and step-free enough for a running stroller or a chair.
- Trail mapOfficial trail map
- Websiteopenspace.org
- Phone+1 650-691-1200
- Social Instagram · Facebook
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