GPS units on Denali backpackers: tracks bunch up despite “Find Your Own Trail”

A backpacker admiring the view of Mount McKinley. NPS/Kent Miller.

Denali National Park and Preserve tells backcountry visitors to "Find Your Own Trail", yet when researchers put GPS units in backpackers' hands in the summer of 2016, the tracks piled up in a few places. The study was written up in Alaska Park Science by Rose Keller of the Norwegian Institute for Nature Research and Lorraine Foelske of the Bureau County Soil and Water Conservation District, and this page paraphrases it. It was part of a larger project on visitors' values and pro-environmental behavior.

Why track backpackers

Knowing where visitors go helps managers use resources well, spot damage such as trampled vegetation and soil erosion, and protect other visitors' experience. Denali covers six million acres of subarctic land, includes two million acres of designated wilderness, and is mostly trailless. Visitors are told to avoid informal trails, a policy meant to spread use over fragile tundra. The park has 87 backcountry units, and the units in the "old park" have nightly quotas that are often met from June through August. The 92-mile park road is the usual launching point.

Managers worry about a growing network of informal trails and concentrated impacts around popular routes. Managers rely mainly on seasonal monitoring (trail counters, patrols, photographs, erosion checks), and occasional patrols are the only way to enforce dispersion. Trail counters only record where they are installed, so they miss dispersed travel. GPS units, in wide recreational use since the early 2000s, record actual movement and can be tied to survey answers.

How it worked

In June through August 2016, backpackers who agreed to take part carried a Canmore GT-740 FL unit, one per group, and returned it on the way out, with a drop box outside the backcountry office for any hour. Researchers also met willing hikers on their return to collect units and run a follow-up survey. Guided groups were included for comparison.

In all, 147 units went to 132 independent groups. After cleaning, 113 trips remained: three units never came back, and others held no or incomplete data, often because the hiker forgot to switch the unit on. Cleaning removed points in the frontcountry, points that were physically impossible, and dense clusters where a hiker was standing still, which cut each group's distance by an average of 4.7 miles (7.6 km).

What the tracks showed

• Trips lasted about three days and covered about 11 miles on average; the longest ran ten days.
• Tracks were densest near the Eielson Visitor Center and the Toklat River Rest Area.
• Over one third of backpackers (37.5%) entered the backcountry from two stretches of the road, miles 50 to 55 and miles 65 to 70.
• Backcountry Unit 13 (Mount Eielson) saw the most hiking, followed by Units 9 (East Toklat) and 10 (West Toklat).
• Of 203 campsites, most were in the middle of the road between Toklat and Eielson. About half were within view of the road, although staff ask backpackers to camp out of sight.
• Most backpackers camped on vegetated ground, most often low shrubs (41.9%), then bare ground (17.7%).

Independent hikers spent the most time out (on average 2.89 days, two-day trips most common) and went farthest, averaging 11.08 miles. NPS-led day hikes lasted one day and averaged 2.67 miles, and guided educational trips averaged 2.30 days and 5.97 miles.

Why the clustering

The authors offer four reasons. The densest tracks were at higher elevations, where walking is easier than in the boggy, brushy lowlands. Backpackers probably sought similar scenic views. The busiest units are well known. And people may stay near established road stops such as Eielson, which have bathrooms and water, before they set out.

What managers can do with it

Denali has made backcountry tracking a priority since its 2006 Backcountry Management Plan. Season-long data such as these can guide permit staff in reinforcing both the "Find Your Own Trail" message and the advice to camp out of sight, and show where to monitor tundra for impacts. The study also showed that guided, NPS-led and independent hikers have very different experiences of time and distance. The authors expect GPS tracking to keep improving as a way to understand use in remote areas.

Sources

• Rose Keller (Norwegian Institute for Nature Research) and Lorraine Foelske (Bureau County Soil and Water Conservation District), Using GPS units to understand where backpackers travel in Denali National Park, Alaska Park Science 20(1), National Park Service; rewritten in hubnx's own words.