Comprising nearly 1,200 square miles that's more than 94 percent wilderness, Yosemite National Park is one of California's best-known national parks. Yosemite Valley is the main point of access to the park. Nearly 4 million people visited Yosemite in 2019, according to the National Park Service, and many of them spent all or part of their time in Yosemite Valley. Such heavy recreational use in this relatively tiny area of the park has enormous potential to damage the valley ecosystem, harm local wildlife, and scar the landscape for future visitors.
Leave No Trace is an international stewardship initiative that focuses on helping people enjoy the outdoors responsibly by minimizing their impact on natural areas, thereby protecting and preserving local plants and animals and keeping the area undisturbed for others to enjoy. Leave No Trace is a set of guidelines for all visitors to follow – they're not just for the pristine Yosemite wilderness. In many ways, Leave No Trace ethics are most important for visitors to Yosemite Valley because careless actions by even a fraction of the millions of visitors there become readily apparent.
Leave No Trace and Yosemite Hiking
Most Yosemite Valley visitors plan day hiking trips on the many Yosemite trails that start in the valley. Although Yosemite Valley is a developed area, day hikers don't even have to walk a mile off the main roads to reach areas that are designated wilderness. Leave No Trace for day hikers visiting Yosemite means packing out all trash. Hikers should be mindful of the items they bring and avoid dropping or leaving behind tissues, food wrappers, clothing, plastic bottles, or food.
On many Yosemite Valley trails, hikers have limited or no access to facilities once they leave the trailhead. In trail areas where no restrooms are available, Leave No Trace ethics directs visitors to pack out toilet paper and sanitary products. Visitors should bring a small shovel, toilet paper, and a small plastic bag on Yosemite hikes and dig cat holes for solid human waste 100 feet from water and trails. Nothing is more unsightly or unsanitary than waste and toilet paper along trails.
Hikers should also follow designated trails – single file if necessary – and avoid cutting through switchbacks and creating "social trails." Hikers should wear durable shoes so they can stay on the trail even if it's muddy or wet. Another Leave No Trace ethic for hiking in Yosemite is respect for others' Yosemite experiences. By yielding to others on trial, using hushed voices, and taking breaks off to the side of the trail, hikers allow one another to enjoy the sounds of nature and the solitude of Yosemite. The maximum hiking group size is 15 people on Yosemite trails.
Leave No Trace and Yosemite Camping
Leave No Trace ethics direct campers to choose durable surfaces for campsites and camping activities. In heavily used and popular areas like Yosemite Valley, this guideline means that campers should set up camps in designated or developed sites only and keep vehicles, tents, and equipment in these areas as well. Campsites shouldn't be altered by cutting down trees or digging up plants or earth, and campers should restrict activities like picnicking and playing to graveled areas and spaces without vegetation. Yosemite Valley campers should keep their campsites tidy and avoid littering, spilling food, or allowing trash or plastic bags to blow away.
Yosemite Valley campers who build campfires should minimize their impact by making small fires and restricting them to fire rings or pits that are already present at their campsites. Leave No Trace ethics to discourage – and Yosemite Valley regulations prohibit – cutting firewood, including pine cones and pine needles, from living or dead trees. Campers can purchase firewood in Yosemite Valley or in small towns on the way to the park. An important part of Leave No Trace ethics is avoiding the spread of non-native species and forest pests. For a Yosemite trip, this guideline means that firewood should be procured within 50 miles of the park.
All wood should be burned to ash, trash should not be burned in campfires, and fires should be extinguished completely when unattended.
Leave No Trace and Yosemite Wildlife
A Yosemite vacation is enhanced by the presence of a wide variety of wildlife that calls Yosemite Valley home. Leave No Trace ethics to highlight the importance of respecting wildlife by keeping distant and not disturbing local animals, especially during sensitive times when they are mating, nesting, or raising young. Visitors should obey posted speed limits in Yosemite and watch carefully for wildlife, especially juveniles who are still learning the dangers of vehicles.
Visitors should never feed Yosemite wildlife, even inadvertently, by spilling or discarding food or trash on the ground. They should also leave pets at home or make sure that they are leashed and supervised at all times to protect wildlife. Pets are permitted only on paved trails in Yosemite Valley.
Visitors to Yosemite Valley must be particularly mindful of black bears. Once habituated to human food, Yosemite bears will break into cars, coolers, and campsites to get it. Yosemite Valley visitors must store food and scented items properly in provided food lockers and discard trash and recyclables in bear-proof receptacles; these items must never be left in vehicles or unattended at a campsite or in a backpack. Although negative encounters with Yosemite bears are decreasing in Yosemite Valley, human carelessness continues to endanger the lives of bears and set the stage for bear–human conflict.
Practicing Leave No Trace in Yosemite Valley
Just as collective carelessness in Yosemite Valley can lead to habitat destruction and damage to wildlife, thoughtful practice of Leave No Trace ethics can make a noticeable difference in the valley's appearance and wildness. If every individual visiting Yosemite Valley uses the area responsibly and carefully, it will remain a natural and beautiful place for generations of plants, animals, and humans alike.