Into the canyon

With each step, my boots kicked up little clouds of yellow dust. The desert sun shone brightly, pushing my shadow along in front of me. The click-click-click of my friends' walking sticks marked the pace.

My eyes and ears wanted to stay on those details because when I looked up a great void opened before me, and it made me dizzy. From where the four of us walked, just below the rim of the Grand Canyon, it was nearly a mile down to the Colorado River, and 10 miles to the North Rim. In between, an abyss yawned, ringed by striated cliffs that seemed to vibrate with color.

When walking, it was a lot easier to look at my feet.

Proportion, perception and scale are all knocked out of kilter in the Grand Canyon. In 1540, Garcia Lopez de Cardenas and his party of men became the first Europeans to lay eyes on it. Standing on the rim, they estimated the river in the gorge to be about 6 feet wide, and that the rocks below were as big as men. Cardenas sent three fellow explorers down to the river, thinking they'd be back shortly. They returned at the end of the day, exhausted and bewildered, saying that the rocks were bigger than the cathedral of Seville, and that they didn't even get close to the river.

Led by Grand Canyon Field Institute instructor Lisa Kearsely, our party of four intended to do what the Spaniards couldn't -- walk down to the Colorado River in a day. Two nights later, we'd walk out.

Kearsely, a biologist and former park ranger, would guide us through the hazards of desert hiking while teaching us about an icon of the American landscape.

The Grand Canyon has changed much since the Conquistadors arrived. The famously clear air is sometimes tainted with smog from as far away as Los Angeles. The Colorado River has been dammed, drained and tamed. Nearly 4 million visitors each year add crowds, lines and parking hassles. The canyon, like most remaining wilderness areas in the Lower 48, is encroached upon from all sides. And yet, from the panoramic vistas to the jewel box-like wonders of the inner gorge, the Grand Canyon retains the power to shake one's soul.

The canyon also remains a dangerous place for fragile, water-dependent creatures such as human beings. Kearsely had spent a good part of the previous day explaining how we would hike from rim to river and back again. The Grand Canyon Field Institute, an independent nonprofit organization in the park, offers learning vacations year-round.

The one I chose last August was called "Mule-Assisted Backpack"; we'd each be sending 30 pounds of camping gear down the gorge on the early-morning mule train; we'd leave later, carrying 20 to 30 pounds, including water, on our own backs.

The Paiute called the plateau Kaibabits -- mountain lying down. For hikers, the canyon is like an inverted mountain. First the descent, then the ascent.

"That fools a lot of people," Kearsely said. "It seems so easy until you start back up. Every year people die because they underestimated it."

The combination of high altitude and desert heat can be the undoing of even a fit athlete. The climb out of the canyon is a feat similar to summit day on Mount Rainier, with an elevation gain of nearly 5,000 feet. Nine people died on the canyon's trails in 2004, and more than 250 had to be rescued, most because of heat exhaustion.

Stepping back in time

Other potentially fatal hazards covered by Kearsely included falling, lightning strikes, rattlesnakes, scorpions, drowning and hyponatrimia, which is when you drink too much water without replenishing minerals and salt.

Heeding her advice, I carried more than a gallon of water and a supply of salted nuts. My fellow travelers were two women, a psychologist celebrating her 60th birthday and a 41-year-old audiologist, both coincidentally from New York. Kearsely, 44, lives in Flagstaff. She's a lean, plainspoken mother of two. She let us set the pace, following close behind, often stopping to offer insight.

"They say with every step you take into the canyon, you're going back 20,000 years," Kearsely said, pausing in the shade by a sheer wall of yellow stone. "By the time we get to the bottom, we'll be looking at rock that's 2 billion years old."

"Take a closer look here, you can see all kinds of sea life," she said. She pointed out little fossil seashells and remnants of coral that lived in this part of the continent 250 million years ago when it was covered by an inland sea.

The next layer down, a few million years deeper in the past, was an even paler yellow, which Kearsely pointed out was an area of calcified sand dunes. "It was a free-blowing area of dunes bigger than the Sahara," she said.

Thus the morning went -- inland seas, mucky swamps and evidence of long-gone creatures: a million years every 50 steps. The sun got hotter. A mule train passed us coming up the canyon, leaving us in a cloud of dust.

The Kaibab Trail is 7 miles long. We went through steep switchbacks, across open plateaus and then down more switchbacks. The canyon walls rose above us, bit by bit. We passed by a field of agave plants, giant flowers on bright green, bamboolike poles 15 and 20 feet high. Kearsely said that the agave stores moisture and energy in its root ball for 20 or 30 years, and then in one explosion of passion, sends up that glorious flower to reproduce. Then it dies. Such is life in the desert.

By midafternoon, ankles and knees beaten from walking downhill for seven hours, we reached the river. It was nearly as wide as the Mississippi at St. Anthony Falls, and much faster moving. We crossed narrow Black Bridge and walked into the side canyon carved by Bright Angel Creek. Tall cottonwood trees threw down welcome shade.

Big battles over dams

We passed a thermometer declaring it was 110 degrees, and staked a claim on one of the campsites lining the creek. Hikers who'd arrived ahead of us were already sitting on their haunches in the 2-foot-deep creek, trying to cool down. We threw down our packs, drank our fill of cold water from the shared tap and then sat down in the creek in front of our camp. It was blissful.

After a nap and a rehydrated dinner (mine was turkey tetrazzini), we walked back down to the river and sat on the beach. The sun was already behind the canyon walls, and the sky was a deepening shade of blue.

The Grand Canyon has been the site of two major, national environmental battles. In the 1950s, the federal government proposed a dam upstream of the Grand Canyon to collect drinking water and generate power for the growing cities of the Southwest. Conservation groups wanted to save what would be lost under water: gorgeous slot canyons, Anasazi ruins and plants and animals that hadn't even been discovered yet. Dam supporters won the day. In 1963, Glen Canyon Dam was completed.

Two similar dams were proposed in the Grand Canyon. Led by the Sierra Club, opponents of the dams persuaded Congress to reject the proposals. A brilliant ad campaign was considered the pivotal blow. Responding to Corps of Engineers assertions that flooding the inner gorge would allow more people to enjoy the Grand Canyon, the Sierra Club took out full-page newspaper ads asking this question: "Should we also flood the Sistine Chapel so tourists can get nearer the ceiling?"

That victory was tempered by the unanticipated effects of Glen Canyon Dam on the Grand Canyon. "People knew what would happen upstream," Kearsely said. "But they didn't pay much attention to what would happen downstream. And here we are, 90 miles downstream in a much-changed environment."

Before the dam, the Colorado was a warm, silty river that flooded massively in spring, carrying 4 to 5 tons of silt and sand downstream every second, she said. It scoured the shoreline, tearing away the previous year's vegetation and creating new sandbars and broad beaches.

A river transformed

The dam ended all that. River flow was regulated according to the power needs of growing cities such as Phoenix and Flagstaff, not natural cycles. Further, the dam trapped the silt that normally would make new beaches. Because the water was released from well beneath the surface of newly created Lake Powell, it was clear and typically colder than 50 degrees. Several species of fish couldn't survive in the radically altered river, and several other species are still in danger of extirpation. Beaches have steadily eroded and invasive species, such as the tamarisk tree, have taken over parts of the shoreline that are no longer scoured in annual floods.

Kearsely pointed out a line of gnarled mesquite and catsclaw acacia trees, nearly 40 feet above the river. "That's the old flood line. You'll notice there aren't any young acacias or mesquites growing; without that floodstage, they can't reseed."

Kearsely said she and her husband, also a biologist, participated in research projects on how the dam affected the downstream environment, and that the story is never simple. While tamarisk trees crowd out native species, they also provide needed nesting sites for willow flycatchers, a rare songbird.

"You have to decide what's good versus what's bad. There used to be no vegetation here, now there is," Kearsely said, looking around at the overgrown shoreline. "Some people talk about decommissioning the dam, turning the Colorado back into a warm, silty river. But you can't go back. The tamarisk will still be here, and the native fish will still be gone. It will never be the way it was before."

The sky was getting dark. We heard a couple of yips, and spotted a fox about 50 feet away. He sat placidly outside his den, sniffing the evening air and getting ready for the night's prowl, completely unconcerned with us.

I was exhausted, and it was still hot. My cohorts wandered down to the Phantom Ranch canteen, which becomes a beer hall each night for the backpackers and mule passengers who are staying over. I laid down on my sleeping bag in my shorts and looked up at the sky. I didn't bother putting up my tent.

Down by the river, there was a bulletin board with notices and warnings for hikers. A flier said to be sure to enjoy the night sky. "Did you know that only 10 percent of the world's population can see the Milky Way? The rest live in areas where the night sky is so polluted with artificial light that only the brightest stars are visible."

The sky above me was somewhat constrained by the walls of Bright Angel Canyon, but the Milky Way was as vivid as the cliff faces had been in daylight. I saw a couple of falling stars, and watched the stately passage of at least a dozen satellites, beaming messages that, thank God, weren't for me.

I live in a city where I cannot see the Milky Way, or even satellites, so I enjoyed lying there, breathing the desert air, sweating and imagining the billions of years it had taken for that light from the stars to reach my tiny eyes.

Many things are lost and gained when people impose their order on the natural world. What I felt that night, as part of the privileged 10 percent of humanity that could see the Milky Way, was that the biggest loss may be awareness of what was lost in the first place. Many people live and die without ever seeing the Milky Way, and many people live and die without setting foot in a wilderness. They can never know the beauty and power of a place that manages and orders itself. Ultimately, that's the greatest danger to the wild places that remain. Why would anyone want to save a wilderness if wilderness is just an abstract concept?

For our small party in the inner gorge of the Grand Canyon, the evidence was tangible. We soaked under waterfalls, spotted bighorn sheep and mule deer, and took a long nap on a big flat rock in the shade. All of those places would have been under water had the Colorado been dammed in the canyon.

We got up before sunrise the next day and, with a sense of sad nostalgia, began the hike out. The view from the rim of the Grand Canyon almost always inspires humility, a sense of how small and short a human life really is. The 10-mile climb out of the canyon in desert heat with 25 pounds on my back enforced that sense exponentially. It took nine hours to reach the trail head on the South Rim.

Dust-covered and exhausted, I looked back down. No longer an abstraction, the view had meaning, earned with sweat and sore muscles. A mile below, the Colorado River carried on its steady, slow work, grinding the floor of the canyon and carrying the detritus downstream, speck by speck, as it has for millions of years.

Chris Welsch is atwelsch@startribune.com

Chris Welsch • 612-673-7113