I wasn’t expecting to be quite so wonderstruck by Yosemite. After all, my husband, Jim, and I had seen hundreds of mountains, from Colorado to Alaska.

We’d been to all the other great Western national parks, and decided to round off our list with a Yosemite tour by Road Scholar. This five-day, mid-October trip featured David Lukas, a naturalist and author with the soul of a poet.

Iconic images

Our adventure began in San Francisco, where we joined a group of 30 other people and took a bus through the drought-stricken agricultural heart of California to the park entrance. All chattering stopped when we arrived at Tunnel View overlook and got our first sight of the iconic Yosemite Valley. For several minutes after we exited the bus, the only sound was the clicking of cameras. Lukas joined us the next day, and we bused to a meadow just across the road from El Capitan, a vertical rock formation made of granite, a daunting challenge for rock climbers from all over the world.

Lukas pointed to El Capitan, where I caught the glint of sun on metal and saw a tiny human figure dangling in a harness. Incredibly, the climber briefly landed on a ledge that was too small to see, then ran as fast and as far as her ropes would allow before swinging back across the face of the rock. She was striving to reach a crevice she could dig her fingers into and pull herself to a slightly lower shelf. After several tries, she finally succeeded. There was no telling how many days she’d already been on El Capitan, or how much longer it would take for her to get all the way down. Until I saw how small she looked from the ground, I hadn’t grasped El Capitan’s massive size.

The miracle at our feet

Later we stood on an outcropping of granite so smoothed by ancient glaciers that it looked like sandstone.

“Pay attention to the miracle happening at your feet,” said Lukas. "As the rock erodes, it creates grains of sand, making the dirt that allows trees and plants to grow.”

The sandy soil glistened, but it didn’t look like promising ground for the soaring trees just a few yards away.

“By itself, the sand and its minerals wouldn’t support growth, but it mixes with rock and tree lichen, binding them together and adding nutrition,” Lukas continued.

I’d thought the chartreuse stuff growing on the trees was moss, but not so. The Sierra Nevada Range’s plutonic granite lies just a few feet beneath the park’s surface, impenetrable to roots. That meant the trees had a shallow, interlacing root system but no taproot. The patient and unassuming lichen gave trees the backbone to grow.

Dead and dying trees were everywhere in the park, evidence of bark beetles that were taking advantage of the drought-weakened ecosystem. Lukas told us that deep in the forest he’d heard the insects chewing as they ate their way through the bark. We examined the trails they left on the denuded, fallen tree trunks. It was easy to see death in the beetle-killed trees, but there was also a kind of beauty in the bleached trunks with their fine lines.

Bark beetles are opportunists. They can’t kill healthy trees but play a significant role in a weakened forest by preparing it for the next generation. Dead trunks and limbs make fuel for fires that cleanse the forest floor and added nitrogen-rich ash. Seedlings that would never have had a chance in the old growth forest begin their journey skyward. Moreover, the infestation of beetles draws birds to the park in record numbers.

Falling stars

The next day, the tour took us far up the Tioga Road. At the higher elevation, we got a sense of just how big the park is and how much of its rugged backcountry is inaccessible, except to the hardiest of backpackers. We ate our lunch on the mica-flecked sandy shore of Tenaya Lake.

Lukas set up his scope and pointed out a couple of rare great gray owls. While he was talking, a Parnassian butterfly, a species that lives only in the Sierras, drifted past. His practiced eye missed nothing.

That same evening, we bought tickets for a presentation under the night sky. The park service limits light pollution in Yosemite, and the darkness quickly swallowed our flashlight beam, causing us to lose our way. Eventually, we got to the proper meadow, but clouds had gathered after a sunny day, and with a three-quarter moon on the rise, the stars were mostly invisible. The astronomer offered to refund our money, but everyone elected to stay and urged him to tell us what we might have seen if nature cooperated.

We came away from the talk with fresh appreciation for the vastness of space and our little place in it. Across the road, we saw the flickering headlamps of climbers making a night-time descent from El Capitan. Their lights looked like falling stars as they rappelled down the cliff.

Something special

On the last day of our Yosemite experience, Lukas promised us something special. We followed him and his scope a half-mile uphill to a viewing area near the base of Bridalveil Fall. Bridalveil, though not the roaring behemoth it is in spring, still had water that fell in a dancing, coruscating cascade to the stream below. The wind made a fine mist of the water as it plunged, and it was easy to see how the waterfall got its name. According to Lukas, Native Americans called it Pohono, after an evil god who blew an ill wind. When it was my turn to look through the telescope, I gasped. The water’s dance began the moment it began its plummet. As it met the resistance of the strong canyon wind, it was lifted up, catching the sun. I immediately thought of the dancing fountains at Las Vegas’ Bellagio Casino and wondered if Bridalveil inspired their design. If so, they were a pale imitation.

On the last night, people lingered to say goodbye to each other and our hosts. Everyone was reluctant to return to our everyday lives. The bus trip back to San Francisco was quiet. Jim and I spent one more night in the city, but didn’t linger. The city lights and noise jangled our nerves.