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McAfee Knob on Virginia’s Blue Ridge is an iconic location along the Appalachian Trail. Photo: Emma Frances Logan/Unsplash

Hiking may just be the best way to experience nature, moving along a trail on just your two feet, your boots crunching on the ground as you traverse the natural world. One travels slowly, slowly enough to appreciate your surroundings and consider your place in the world.

But there are iconic trails where that sense of peace is rapidly changing or threatened to cease altogether. Whether it's the rapid retreat of a glacier due to climate change, or overcrowding on a world-famous thru-hike, many trails in the United States are changing in ways that we couldn't have imagined a few decades ago.

Below are four hikes that could look very different in a few short years. They're worth checking out before that happens, and if you like what you find, consider joining the various efforts to protect them.

Exit Glacier Trail, Kenai Fjords National Park, Alaska

Glaciers like this one are rapidly retreating in Kenai Fjords National Park. Photo: Phillip Sauerbeck/Unsplash

Threat: Climate Change

The draw of this hike is changing rapidly with each passing season. In 2017, Exit Glacier Trail – accessible from a mellow, 2-mile trail from the Kenai Fjords National Park – retracted by a staggering 293 feet. Just as concerning: It continues to retreat even during the winter, an especially striking change from normally below-freezing Alaskan temperatures.

Park officials have recently extended the trail twice to reach the toe of the glacier with its sky-blue ice and constant cracking. This hike is extremely popular for good reason: It's stunningly beautiful and is the only easily accessible glacier in the park (the rest require backcountry travel or boat access).

Drive 12 miles north from Seward and park at the Nature Center. Head south on the well-maintained trail and take in views of the Resurrection River before stopping at Glacier View to check out Exit Glacier from a distance before climbing up to the toe of the retreating glacier itself. Make sure you take pictures; it will look different the next time you see it.

The Appalachian Trail, Georgia to Maine

Find out why they call them the Great Smoky Mountains on the Appalachian Trail. Photo: Isaac Wendland/Unsplash

Threat: Overuse

The 2,189-mile Appalachian Trail from Georgia to Maine is a classic example of something being loved to death. In the current decade there has been a 43-percent increase in thru hikers on the AT, according to the Appalachian Trail Conservancy (ATC). Part of that comes from the popularity of the books “Wild” and “A Walk In the Woods,” and their corresponding movies (“Wild” was about the Pacific Crest Trail but shines a pop-culture light on thru hiking).

But those hikers only number in the thousands, with only 20,000 finishing the trail since 1936. According to the ATC, there are 2-3 million visitors to the trail for day-hikes or shorter backpacking excursions. Hot spots like Maine's Mount Katahdin, Clingman's Dome in Great Smoky Mountains National Park and The Pinnacle in Pennsylvania are all highly popular and well-visited destinations that put a strain on the various amenities along the trail (toilets, trash cans) as well as do damage to vegetation and the trail itself.

Over 2,000 volunteers put in over 200,000 hours of labor each year to keep the trail in good condition, and the ATC continues to be at the heart of the effort. While more people using the trail potentially mean more people to protect it, that work requires large amounts of time, labor and resources. In the years ahead, it will require a fine balancing act to protect the AT, one of the most popular trails in the United States.

There are endless ways to enjoy the AT as it crosses no fewer than 14 states. But why not start at the beginning? You can choose from either end: Springer Mountain, Georgia, offers a mile-long hike along a fire road to the mountain’s summit with stunning views and the southernmost blaze on the AT. On the north end, the centerpiece of Maine’s Baxter State Park is the challenging and famous Mount Katahdin. Make sure to reserve a permit and check the weather for this one.

San Joaquin River Trail, California's San Joaquin River Gorge, California

The San Joaquin River is a treasured respite for hikers, mountain bikers, kayakers, and more. Photo: Richard E. Ellis/Flickr

Threat: Dam

There is never enough water in California. With a population that continues to grow and a thriving agricultural industry, the state with the fifth-largest economy in the world continues to demand more resources, and water has always been at the center of the struggle.

Case in point: Upstream from Fresno in the Sierra Nevada foothills, the 11-mile San Joaquin River Trail is a favorite for wildflower enthusiasts, mountain bikers, hikers, runners and equestrians, not to mention the kayakers who frequent the river itself. But an almost $3 billion project, called the Temperance Flat Dam, threatens to flood the whole area.

This project would provide agricultural water for farmers in the Fresno area as well as provide a safeguard for communities in a state that is plagued by drought. While funding for the proposed 600-foot dam is still in its early days (the project received $171 million in funding in 2018 of the total price tag of $2.83 billion, projects such as this tend to lie dormant, then push ahead quickly.

To experience this trail, follow CA-168 to Auberry and follow Auberry Road to Smalley Road, which you'll wind along for 9.1 miles to the trailhead. Bring plenty of water, especially in the summer. Of course, that might not be a problem in the future.

Border Route Hiking Trail, Boundary Waters Canoe Area Wilderness, Minnesota

Exploring the Boundary Waters Canoe Area Wilderness by foot or by boat should be on your bucket list. Photo: Josh Hild/Unsplash

Threat: Sulfide-Ore Copper Mining

The Boundary Waters Canoe Area Wilderness is one of the most iconic conservation zones in the United States, covering one million acres of lakes, forests and trails. The area has been a haven for Midwestern outdoor enthusiasts since it was protected by the Wilderness Act in 1964. Adventurers from around the world flock here in the summer and fall for multi-day adventures both in paddle craft and on foot.

But mining pressure is currently growing within miles of the area's margins. Roads, railways, and buildings are being approved for sulfide-ore copper mining, and byproduct contaminants such as sulfuric acid, copper, mercury and others pose a threat to the pristine watersheds in the wilderness area that make this region an international draw. The Northeastern Minnesotans for Wilderness are campaigning to "Save the Boundary Waters" from pollution that could affect the heart of the area for hundreds of years as well as affect the thriving tourism economy that BWCAW draws.

While it's best known for canoeing, there are countless miles of trails exploring the area, including the 65-mile Border Route Hiking Trail, which will take you by expansive lake vistas, stunning cliffs, old growth timber and surging waterfalls as you straddle the border between northeastern Minnesota and Ontario, Canada.

The trail can be accessed at multiple points for short day-hikes or multi-day excursions, with the nearest access from Grand Marais or Hovland. Permits are required to camp overnight in the BWCAW and can be acquired at the ranger station in Grand Marais. Exploring this watery world is one for this year’s bucket list.

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