Go with the Flow 
Follow the historic Flume Trail in South Dakota for a road-less-traveled-style summer excursion.
On a summer Friday, my husband, Chris, and I skip out of work early and head into my personal version of travel hell: the overcrowded Black Hills of South Dakota. Home to summer rituals that ooze Americana, like treks to Mount Rushmore National Memorial (nearly three million annual visitors) and the Sturgis Motorcycle Rally (another 400,000 to 500,000 tourists), this destination is anything but undiscovered. But year after year, we pack up our car with camping gear—the tent, the stove, the air mattress, and the s'mores fixins—and migrate north to Sheridan Lake, a tranquil reservoir just 14 miles from where those American presidents sit chiseled into the mountain. Here, at Sheridan Lake, we can escape the teddy bear-laden gift stores, avoid the strings of RVs teetering along the Needles Highway, and steer clear of the ice cream cone stands. Here, we can hear the wind rustling through the pine needles above and inhale the ponderosas' perfume. Here, we can reminisce.
As we grew up—and years before we even met—both of our families vacationed in the Black Hills. Sitting around the campfire now, listening to the sap from the logs popping and hissing in the heat, we share memories of this same place from ages six, eight, 12, and beyond. That old pop-up camper. A wildflower coloring book. A first crush. For both of us, though, one memory stands out: hiking along the historic 11-mile Flume Trail.
"They look like a toy version of the Rockies," Chris says as we drive through the canyons of the Black Hills. I have to agree. The rocks here are less jagged than in Colorado, the peaks are less intimidating, and even the colors of the dark pines and spruces seem softer, more muted. For miles, the South Dakota prairie undulates to the horizon. And then peaks suddenly rise out of nothing. Known to the Sioux Nation as the Paha Sapa, the area was seen as a sacred, spiritual, and rehabilitating place. That all changed when gold was discovered in the rock and streambeds in the 1870s. Prospectors poured deep into the Hills, leaving a string of homesteads and towns (Deadwood, Hill City, Lead) in their wake. Gold, it seemed, was everywhere, including in the tiny mining settlement of Rockerville.
The problem was extracting it. The Rockerville miners needed a water source to soften the compacted soils of the placer deposits so they could sluice out the gold. But the nearest water source was about 17 miles away. To solve the dilemma, they settled on a grandiose engineering plan to create a giant wooden flume to channel the waters to town. A dam would hold back Spring Creek, near Sheridan Lake. Two tunnels would be drilled through solid rock. Trestles—some 80 feet tall—would help guide the wooden-plank trough downhill.
The plan worked—for a while. After about a decade, the high-maintenance flume (a worker used to walk its length daily to plug leaks with rags) fell into disrepair. Planks were carried off to build nearby ranches or barns. The trestle remnants rotted and crumbled. The tunnels periodically flooded. Moss, ferns, grass, and wildflowers covered the retaining walls. Slowly, the whole ridiculous contraption simply faded into the landscape.
A mile and a half from the Calumet Trailhead at Sheridan Lake, the Flume Trail runs smack into the side of a mountain. At least it would, except for the tunnel that's been blasted though the dark rock. Reinforced with wooden planks in the late 1980s, the tunnel's gaping mouth was the stuff my childhood nightmares were made of. Today, I duck down and step into blackness. I slide one foot forward on a wood plank—a makeshift bridge over the precipitation that has pooled on the floor—and hear water lap against the walls. So much for childhood dreams: This tunnel still gives me the creeps. As my eyes begin to adjust to the darkness, my husband grabs my hand and leads me forward.
He, too, has childhood memories of this trail and offers anecdotes as we make plans to traverse the whole out-and-back trail in one day. It's an ambitious 22-mile trek, but we're bolstered by an early start and anxious to see the trail's end—for the first time. Each time we've started on this hike, we've walked a little farther. As kids, we barely had the energy in our little legs to make it to this first tunnel. As teenagers, we slogged past this point—a little more than two miles, one way—to a second tunnel. As adults, we have trekked a little farther each time we've tackled the route.
While we saw a handful of fellow hikers scattered on the first expanse of trail—the section that follows the Centennial Trail for about a mile along the lakeshore—we're alone now, except for the occasional white-tailed deer or bluebird. This route is designated a National Recreation Trail, making the historical route a protected entity only open to foot traffic. The path follows the gentle downhill grade of the old flume bed, meaning this hike is more of a stroll than a workout. The two tunnel passages are early highlights, but we also keep an eye out for ruins along the trail. It takes a while for our eyes to learn to spot the old flume, but the ramshackle remnants are still there, hidden in the overgrowth. Occasionally, we spot an old plank, dotted with rusted square-head nails, bleached gray-white by the sun, and covered with mint-green moss. We walk over what first appears to be a grassy ridge only to see it is actually a pile of carefully laid stones, leftovers from an old stabilizing wall. The hike meanders through aspen groves, ponderosa stands, and open meadows with fields of wild irises.
As it often does in the afternoon here, a soft rain starts to fall. We break for a picnic lunch on a rotted log, and Chris picks wildflowers to place in my wide-brimmed hat. This time, we've managed to traverse nearly the full length of the trail, but we decide to head back because I'm dreaming of roasted marshmallows around the campfire. On the way back to Sheridan Lake and our tent site, we stop to watch a tiny waterfall or smoke curling from a farmhouse's chimney. Mostly, we just talk about the past, the future—and we make plans to come back to this uncrowded piece of Americana again and again, and one day cover the entire distance.
If You Go
The trek from Denver to Sheridan Lake takes six hours by car. Travel north on I-25 for 215 miles. Take Exit 126 to U.S. 18 east toward Lusk, which will eventually move you across the Wyoming/South Dakota border. After 122 miles, turn onto South Dakota Highway 89, which merges after 15.5 miles with U.S. 385 to carry you north into the Black Hills. Follow U.S. 385 to Hill City. Six miles past Hill City, begin following signs for the Calumet Trailhead and the Flume Trail on the southeast side of Sheridan Lake.
Sheridan Lake Campground: 605-574-4402; www.recreation.gov 
The Rocky Loop sites at the Sheridan Lake Campground are at the water's edge (you can even dock a small boat or canoe here), and while the drive-in campground boasts its fair share of rowdy RVers, the massive lots are big enough that you can often see your neighbors' campfires but not overhear their conversations. Backcountry camping along the Flume Trail is allowed, but most people simply set up base camp near the lake.
The Flume Trail: 605-673-9200; www.fs.usda.gov 
This 11-mile (one-way) trail is designated a National Recreation Trail, meaning that bikes and vehicles are verboten. The result is a tranquil and well-marked trail suitable for both families (turn around before everyone gets tired) and experienced hikers.