When approaching one of the many canyons of southwest Idaho, it is easy to have doubts: can such a feature even be possible amid all these flat plains? The crop fields of the Snake River Basin could pass, after all, for the vast lowlands of Kansas or Nebraska. Yet suddenly there it is: heading south toward Twin Falls, for example, the flatlands give way to a precipitous drop of hundreds of feet: to reach the city, on the other side of the canyon, one must either navigate a series of winding roads or cross the nearly 500-foot-tall Perrine Bridge. This is the doing of the Snake River, which over time has carved deep gorges into the bedrock of basalt and rhyolite.
Moreover, below the surface of the Snake River Basin is a vast and overwhelming productive subterranean aquifer, exposed at several points as springs in the Snake River Canyon and its numerous tributary gorges. One of the best places to see this convergence of these features—canyons and springs—is the Earl M. Hardy Box Canyon Springs Nature Preserve, a unit of Thousand Springs State Park that is about 35 minutes from Twin Falls. A short but moderately strenuous trail descends into this magical, basalt-rimmed canyon to reach the beautiful spring-fed waters, which are remarkably clear and colorful, and ends at a roaring, 20-foot waterfall that makes for a good turn-around point.
The constellation of sites that make up Thousand Springs State Park, despite its proximity to Interstate 84 (the Malad Gorge unit is literally within striking distance of the highway), still remains somewhat of a hidden gem. Part of this is due to lack of services or, even active management at all. (Note: Only Malad Gorge is likely to have active staff, if at all.)
The Box Canyon Springs Nature Preserve is no exception—quiet and remote, with no services—although one is likely to run into at least a few other groups of hikers and/or swimmers on a decent, non-winter day. The sandy dirt track leading to the start of the hike probably weeds out some visitors: in theory, this route is sometimes closed to vehicles, requiring hikers to walk an additional mile to the trailhead, but it is usually open to the trail’s start. The parking lot is small and dusty, and there is little except a self-pay station ($6 entrance fee, good for all Thousand Springs State Park sites) to denote that you have arrived.
The one and only path heading from the trailhead is wide and well-trodden, clearly an old road. A short walk across the flat plain leads to the first overlook of Box Canyon Springs—the basalt-laced walls drop precipitously on three sides (hence the “box canyon”), revealing a lush landscape below: dense greenery and turquoise waters. The scintillating pools are fed by the subterranean aquifer, which seeps to the surface in the canyon. The pools give way to a river, which flows down-canyon.
From this initial vista, backtrack a bit and hang a right at the westward path leading to a short, wooden step-ladder that provides passage over a barbed wire fence. Clear the fence and continue straight as the path traverses grassy flats, with the canyon on your right.
While the main trail keeps some distance from the rim, short spurs lead to additional overlooks. Here one can view the right-hand bend in the canyon and again as it cuts back left down-stream. One can spot paths down in the canyon leading both downstream and up to the initial pools: the former is the main track; the latter is a popular side trip that nonetheless risks poison ivy. Downstream, those with a good eye can spot a wooden platform down on the left river bank—this is your destination.
At 0.4 mile, the trail takes an abrupt right turn—it’s time to descend. Taking advantage of a weakness in the basalt walls, the route narrows and drops down a set of switchbacks—in some areas, metal railings and ropes assist with the short but sharp descent. After the bends, the trail bears northward down a grassy and sun-soaked slope with commanding views of the canyon.
At 0.45 mile, hikers reach the base of the descent—the social trail leading to the intro pools heads right here. Stay left and follow the mild path as it weaves through thicker and taller vegetation: at one point it dodges a large juniper.
Through the bushes and small trees, the trail emerges at the wooden platform overlooking a 20-foot waterfall at about 0.6 mile. Follow the trail a little further to reach the ideal picnic spot: a shady, streamside cove with views of the falls and inviting, multihued waters. Swimming, though, is not for the faint of heart: the spring-fed water is very chilly throughout the year.
Because it is so pleasant, leaving this spot is hard, but hikers can either continue farther down-canyon or—the more popular option—return the way you came. The steep ascent back to the rim can be a little jarring but lasts little more than 5-10 minutes. All in all, plan to spend at least 1.5-2 hours at Box Canyon Springs, one of the hidden gems and geological wonders of Idaho.