Mount Umunhum – a Must See in the Sierra Azul Open Space Reserve

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This past weekend, on Saturday, September 8th, I summited Mount Umunhum (please don’t ask me to pronounce it), covering about 8 miles (12.8 km) in 3 hours. All along the journey to the top, you can find stunning views of the Bay Area, building to a fantastic climax of sights from Mount Diablo in the East to the Point Reyes National Seashore in the North. My short TLDR of it is that, if you live in the Bay Area, Mount Umunhum is a must see in the Sierra Open Space Reserve.

Before hiking this trail, I have a couple pieces of advice. If you plan to hike this trail, be sure to go on a clear day; your camera and eyes will pat you on the back for your prudence. Also, be sure to check out my article on hiking basics. No matter your experience level, it is always worthwhile to know the ins and outs of a safe, fun hike.

The Trail – Great for Intermediate Hikers

There are two ways to get to the top of Mount Umunhum, via the trail (shown in blue) or the road (seen in red) as shown on the map above. If you are able, choose the trail. It is a much more exhilarating experience. The trail is straight forward enough; it is a simple in and out trip. By far, the best place for parking is the Sierra Azul Open Space Reserve Mt Umunhum Rd Parking Lot (shown in the upper right-hand corner of the map). When you park there, you will be treated to stunning views all around you.

If you are not into hiking at all but still want the view, you can take the Mt Umunhum road all the way to the top. While I will frown about your choice, you will smile when you glimpse the San Franciscio Bay Area from the top of the mountain. If you follow the road (Mt Umunhum Rd) to the top, then you will reach the summit with plenty of parking to be found.

Overall, the trail is not too steep. There was rarely a moment when I was out of breath. With that said, this trail is good for intermediate hikers. If you are a beginner, then I would steer away from this trail. It does require some physical capability to get up the steep parts.

As you get closer to the top of the mountain, you can find numerous placards with helpful information on the history and wildlife of the area, making for a wonderful learning opportunity. You will be amazed at all the facts and knowledge you can share with your friends and family.

The History – Native Americans and the US Military

Before Mount Umunhum became what you see it as today, the mountain served as a sacred site for the Ohlone tribes. The present day Mutsun and Muwekma tribes still pay homage to the spirituality and ancient history of the mountain in regular ceremonies. For the people who return to the mountain, the word, Umunhum, means hummingbird in five ancient Native American languages. If you come to the mountain at particular days during the year, you can see local Native Americans performing ceremonies in a dance circle on the mountain plateau.

From 1957 to 1980, the outlook served as a watch post for the US military during the cold war. At the top, you can find a large, gray, rectangular building (pictured to the right) pushing itself above the mountain. It housed one of the largest radar towers the world had ever seen, keeping watching over 250 miles off the coast for incoming nuclear missiles. As time passed on though, it slowly became antiquated until its closure in 1980. All throughout California, there were similar facilities able to alert the US military of nuclear strike.

Wildlife – Keep Your Eyes Open for the Golden Eagle

While I did not spot too much wildlife along the trail to Mount Umunhum, I saw a Golden Eagle returning to its nest in the air above the summit. Some animals you may see include the Purple Martin, California Brown Tarantula, hummingbirds of a variety of species, California Tiger Whiptail, lizards, ants, grasshoppers, and butterflies. It makes for a great experience for the avid zoologist.

In addition to all the animals you may see, plants abound throughout the Santa Cruz mountains. You can see coyote mint, deer weed, june grass, showy rabbitbrush, leather oak, rock buckwheat, bushy spikemoss, scarlet beardtongue, canyon liveforever, venus thistle, and much, much more. For any herbalist, this hike is sure to be a good one.

On Top of the Mountain – a Sight to Behold


When atop the mountain, your eyes cannot help but sparkle. The whole Bay Area extends before you like a rich, colorful canvas. It is like Google Maps, but in real life. You can point out Bay Area landmarks and spot famous points, making for a rich, informative experience. The Bay Area comes to life, giving you an idea of what Silicon Valley looks like from above. The rich history John Steinbeck describes springs forth from the pages, illustrating the land and illuminating the beauty he saw.

On a clear, cloudless sky, the view is, in a word, incredible. You will enjoy every minute you are on top of the mountain. The outlook where you will be bound to take pictures provides a 360° of the scenery. From the top of Mount Umunhum, you can see the four major peaks of the Bay Area, Mount Diablo in East Bay, Mount Tamalpais in North Bay, and Mount Hamilton in South Bay.

Final Thoughts

Taking it all in, the Mount Umunhum trail was short and sweet. For an afternoon of fun outdoor adventure, it was splendid. All along the trail, there were regular spots to absorb spectacular scenery; it made me think, “did I really just see that? Wow!” You will be taken aback.

If you are looking for a fun Saturday outing, then Mount Umunhum is the place for you. The hike boasts of colorful vegetation, mesmerizing the eyes and rainbowing the hills in color. Keep a close watch in the skies above; you may spot an eagle scanning the ground for its prey. So what do you say? Are you going to mountaineer Mount Umunhum or go on a hike near you? Grab your gear and hit the trail. You don’t know what lies just outside your door.

If you have any thoughts, questions, or think I missed anything, do not hesitate to comment below and please share this article. Thank you so much and I hope you make it a great day!

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6 Comments on “Mount Umunhum – a Must See in the Sierra Azul Open Space Reserve”

  1. This looks like a beautiful hike! We love hiking, and there really isn’t anything like this in Florida, that is for sure! What is the best time of year to hike this … I mean I don’t want it too hot of weather…in the 60s or 70s would be great!

    1. Yes, it was quite a beautiful hike. I am sure there are trails in Florida. It does have a lot of swamps to see wildlife that is for sure though. I would not discount Florida quite yet. For this hike, I would recommend early Spring or early Fall. I went on September 8th at the beginning of Fall and it was not too bad. It was in the 80s, but there is a lot of breeze and shade to cool you down. I appreciate your question.

      Thank you for sharing and I hope you make it a great day!

  2. Hi Alex,

    I like hiking. Sadly, I’m still very much a beginner. I love trails and seeing the beauty that nature has to offer. Just the picture above is breath taking. I would love to see a bald eagle in my travels.

    1. Hey Lane,

      It is okay to be a beginner. Every great hiker was a novice at some point. It is quite worthwhile to see an eagle. They are quite spectacular.

      Thank you for sharing and I hope you make it a great day!

  3. Wow, this is incredible!

    I wish that I lived closer so I could enjoy this experience as well.

    Would you go back and do it again or continue your exploration elsewhere?

    Thank you for all the photos and a great read!

    Cheers,
    Kahlua

    1. Yes Kahlua, it was quite an incredible hike. I think I would do it again, but in at least a year or two. I have not explored too much of the Bay Area, so I want to see the other parts before I come back to places I have been before. I am sure there is a trail near you that offers great hiking.

      Thank you for sharing and I hope you make it a great day!

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