In the Sacramento Valley: We received an invitation from our niece, Mandy, for a rare opportunity to hike into the Sutter Buttes, a geologic oddity that rises about 2,000 feet above otherwise flat landscape of orchards and rice fields in the Sacramento Valley, the northern subset of California’s Central Valley.

I say rare invitation, as the ‘buttes’ are almost all on private property and access is limited to a small number of tours over just a few months of the year.

We’ve seen this micro mountain range out of the car windows, in the distance, dozens of times and always wanted to get a closer look, but learned that access was very restricted. Until now.

I thought it best to generate a short ‘flyover’ video of Sutter Buttes to help readers better understand the uniqueness of this part of California geology: (Ignore the different colors of the mountains; this is a composite image from two satellite passes)

The buttes burst through the otherwise flat alluvial sediments of the Sacramento Valley floor about 1.6 to 1.4 million years ago, in a series of volcanic events that define this landscape today.

The first eruptions consisted of thick, viscous rhyolite lavas that formed a dome over the site. Then, after about 30,000 years, this original dome was broken and pushed aside by an eruption of andesite and dacite lavas that form the peaks in the center of the buttes we see today. More specific details of the geologic history of the Sutter Buttes can be found here.

So we were excited to put our boots on top of this geology, and capture some images of the landscape and flora, and maybe some vistas of the surrounding Sacramento Valley from this elevated location while we were on our guided tour. Maybe.

We always drive from the coast to this part of the Central Valley across Pacheco Pass, which cuts through the weathered, exposed geology of the Diablo Range at about 1,300 feet (417 meters).

The road passes alongside the 12,000 acres of water in the San Luis Reservoir then descends into the big valley with a view of the lake in front of the dam, and the miles and miles of agriculture beyond.

But not today. There were no vistas to be seen, no lakes to behold. Just fog. Thick, damp, grey fog.

There’s even a name for it: Tule Fog.

We began our hike just under the bottom of the fog, but quickly found ourselves walking inside the mist, with visibility dropping to just a few yards at some stops.

Thinking for a moment that the fog would dampen our experience as much as it was dampening our jackets, my concerns were quickly eased as we made our first stop on the trail with our guides, Kathleen and Greg:

Each stop was a bit of a revelation, as Kathleen and Greg began sharing small parcels of natural history about where we were standing at the moment, turning a routine walk in the woods into an enlightened outdoor experience in the mist.

They explain the composition of a nearby hillside of light colored rhyolite magma, or the latin name of a delicate seed pod on the ground not larger then a postage stamp.

Kathleen and Greg are simply a walking encyclopedia of natural knowledge and experience about the Sutter Buttes; did she just say that you can use a tuning fork at a certain frequency to open a seed pod? 

(Encyclopedia? I’m showing my age here. How about Wikipedia pages in hiking boots?).

So the wide, sweeping vistas of the valley floor I had in mind gave way to the micro-vistas of natural beauty just at arms length.

As we neared the highest point on our walk, deep in the fog, I couldn’t help but notice a now-familiar California geologic feature: ancient boulders of granite, worn smooth by time and split in the middle. Another close encounter with California’s tectonic past.

I’ll close this post with a few additional pictures and a link to the folks that organize these tours, Middle Mountain Interpretive Hikes. I’ve booked another visit in a few weeks to the buttes. It’s a photography hike, which requires a 6 AM start, just before sunrise. Hopefully, just before the fog wakes up too.