Peaks with Purpose: How Three Local Mountain Ranges Keep Nature in Motion

When I set out to create a map of the mountain ranges that define our region, I knew I’d be tracing the outlines of some remarkable places. Working on POST’s GIS team gives me a unique window into the landscapes we protect — a view that reveals not just mountains and valleys, but also the highways, creeks, and cities that shape how people and wildlife move through them. The Santa Cruz Mountains, Diablo Range, and Gabilans each have their own distinct character, but the real magic happens where they meet. Those connections are what keep our landscapes resilient, our watersheds healthy, and our wildlife on the move.

You probably recognize how these ranges punctuate your daily landscape, even if you don’t always realize it. Maybe you’ve glimpsed Mount Umunhum’s boxy summit or the white domes of Lick Observatory on the horizon. Or perhaps, on the drive to Pinnacles National Park, you’ve noticed oak-studded ridges unfurling toward the Salinas Valley. But which range is which — and what makes each one unique?

In this blog series, my colleagues and I hope to make those distinctions clearer — and share plenty of fun facts along the way.

Meet Three Local Mountain Ranges

Three mountain ranges shape our region, each with its unique character and place. The Santa Cruz Mountains rise west, the Diablo Range stretches from the East Bay to the Southern San Joaquin Valley, and the Gabilan Range expands across San Benito and Monterey counties. How these distinct landforms work together truly matters, as they are part of a living system that keeps our lands resilient, water flowing, and ecosystems connected.

The ranges’ varying elevations, microclimates, and terrains are havens for a remarkable range of plants and animals, including rare native species found nowhere else on earth. That’s one reason scientists call this area a global biodiversity hotspot — and why POST’s role in preserving our natural landscapes from encroaching development is vitally important. From cool, shady forests to sunbaked hillsides, the mix of habitats here helps many plant and animal species survive.

In the woodsy, fog-cloaked Santa Cruz Mountains, banana slugs, marbled murrelets, and bobcats thrive.

Sunny and remote, the Diablo Range harbors rare serpentine grasslands with wide spaces for tule elk and golden eagles to roam.

The Gabilans offer rolling oak woodlands where pallid bats and Gabilan Mountains slender salamanders make their homes.

Life in the Lowlands

The land between these majestic mountains matters just as much as the peaks. When safe routes connect the ranges, animals can freely use valleys, foothills, and forested creeks to find food, water, shelter, and mates, and even establish new territories. These open spaces also help plant life flourish. Maintaining this network of protected, connected areas helps our region’s entire ecosystem work in harmony.

Happy Reading!

When I look at these ranges on a map, I don’t just see three separate landforms. I see a living system of ridgelines, valleys, creek corridors, ranchlands, and forests that fit together like puzzle pieces. And every piece matters. That’s why POST’s work to protect and connect these places is so essential: it keeps the whole system in motion. As you follow this series, I hope you’ll start to recognize these ranges the same way I do: as the interconnected, ever-evolving landscapes that make our region such a remarkable place to call home.

Read the Full Series

Part 1 – You’re reading this one!

Part 2 – Decades of Conservation in the Santa Cruz Mountains

Part 3 – Coyote Valley: A Link to the Diablo Range

Part 4 – Heading South: Two Busy Regions Await