Training Week 1: May 16–22

Featuring Mount Umunhum and its Cold War Past

My first full week of training hikes! After retiring at the end of April, I went to the Formula 1 race in Miami, spent the following week in Florida and the week after that in Rome with my brother. I’m excited to be finally executing my training plan!

I returned home on May 15th, so Day 1 was a gentle reentry, but by the end of the week I’d logged nearly 48 miles with over 7,500 feet of elevation gain across six hikes. Not bad for the first week!

A note on Day Type: I’m trying to follow a structured weekly training plan — you can read more about it here.

Saturday, May 16 — Easy
Redtail Loop to Arastradero Creek Loop, Arastradero Preserve (AllTrails)
5.4 mi / 712 ft elevation gain

First hike back after Rome. Hiked with Lee — good opportunity to catch up after a week apart. Spotted a coyote, then later three deer hanging out with a turkey.

Sunday, May 17 — Vertical
Sanborn Loop to Indian Rock, Sanborn County Park (AllTrails)
9.4 mi / 2028 ft elevation gain

Starts with an intense 3-mile, 1,700 ft climb with switchbacks, then mostly level or downhill from there.

Monday, May 18 — Easy
Ancient Oaks, Mindego Hill & Ridge Trail Loop, Russian Ridge Open Space Preserve (AllTrails)
6.3 mi / 1,086 ft elevation gain

Super windy day, which kept me cool on the exposed sections. Nice mix of forest and grassy hills. Beautiful views of the bay and ocean. Added to my ‘worthy of repeat’ list.

Tuesday, May 19 — Recovery (no hiking)

Upper body strength workout, easy Peloton bike ride, and stretching.

Wednesday, May 20 — Moderate
Mount Umunhum, Sierra Azul Open Space Preserve (AllTrails)
8.4 mi / 1,188 ft elevation gain

See featured hike below!

Thursday, May 21 — Long
John Nicholas Trail, Sanborn County Park (AllTrails)
12.2 mi / 1,581 ft elevation gain

Out-and-back ending at Skyline Trail — I continued an extra mile to round it up to 12. Starts flat, then a gentle climb to the turnaround. Best moment: petting a group of four Labrador Retriever mixes on the way out.

Friday, May 22 — Moderate → Easy
Saratoga-to-the-Skyline Trail, Quarry Park (AllTrails)
6.0 mi / 1,093 ft elevation gain

Turned this into an easier day — sore feet and experimenting with new boots. A lovely out-and-back close to home that I hike regularly. You can extend it as long as you like by continuing past the AllTrails turnaround point.

Week Total: 47.7 miles / 7,688 ft

Featured Hike: Mount Umunhum, Sierra Azul Open Space Preserve

At 3,489 feet, Mount Umunhum is the 4th highest peak in the Santa Cruz Mountains. The trail starts in a parking lot on Mt Umunhum Rd, climbing 4.1 miles and nearly 1,200 feet through beautiful redwood and oak forest on a well-maintained switchback path. It’s a steady, satisfying climb that is not too intense.

But the real payoff is at the top.

The summit offers a truly spectacular 360-degree panoramic view — on a clear day you can see from the Bay to the Pacific, up the peninsula and down to South Bay. Since I was there on a weekday I had the place to myself. I stood up there for a while, slowly turning in circles, just taking it all in.

What makes Mount Umunhum particularly unique is its history. The summit was home to Almaden Air Force Station, a Cold War-era radar surveillance post that operated from 1958 to 1980. The hulking 85-foot radar tower known as ‘The Cube’ previously housed an AN/FPS-24 radar, and still stands at the summit as the only remnant of its military past, before it became an open space preserve. Interpretive displays around the summit cover the military history, the local flora and fauna, and the indigenous peoples who called this region home long before the Air Force arrived.

I’ll definitely be making this a regular. If you’re in the South Bay and looking for a hike with serious payoff, this is it.