The Adverse Effects of Ecotourism as Seen in Yosemite National Park

When the idea to preserve a natural area in Eastern California was first introduced in the summer of 1864, it resulted in just under sixty square miles of land entrusted to the state government, little of which received many visitors. Following its declaration as a national park in 1890, Yosemite’s popularity grew, and it is now one of the most celebrated natural destinations in the United States. The approximately 750,000-acre park consistently receives three million, if not four or five million visitors annually, each vying for a glimpse of headline attractions such as the Half Dome or Glacier Point. Unfortunately, the anthropogenic impact of high visitation has resulted in trampled vegetation, excess litter, and noise pollution—all of which worsen the visitor experience. Similar instances of environmental degradation are appearing across nearly all large-scale parks and monuments in the country. Inaction and the lack of feasible solutions call into question the future use of America’s national parks.

When the National Park Service was officially founded by Woodrow Wilson in 1916, there were only 326,506 recreational visits across all national parks that year. Now, over a century later, visitation numbers have reached well over 300 million recreational visits per year for the past five years, excluding 2020—a year skewed by COVID-19. With a spike in visitors comes what many describe as “amusement-park-style lines” at park entrances and campgrounds, on trails, and in rest areas. Such overcrowding in national parks has been referred to as “greenlock,” or gridlock in natural surroundings, and is common in well-known parks like Yosemite, Yellowstone, Grand Canyon, and Great Smoky Mountains. Today, approximately half of all recreational visits occur within just five percent of all national parks, meaning that the most popular destinations, such as Yosemite National Park, will continue to experience the most intense effects of overcrowding. 

One of the major problems caused by overcrowding in Yosemite National Park is the degradation of the natural ecology, which threatens the safety of both the environment and its visitors. Trampled vegetation severs the habitats of native plant and animal species. Eroded trails endanger the rooting of plants and nearby water quality. This ecosystem destruction also forces Yosemite’s animal populations to either adapt or die trying. In some extreme cases, visitors have even been involved in aggressive encounters with wild animals on trails, near campgrounds, or on off-trail areas. These interactions are both dangerous for visitors and unsustainable to natural ecosystems.

Increased visitation to Yosemite has generated a worrying amount of pollution too, with trash cans overflowing, and litter collecting near parking lots or even along trails. Although the park service encourages visitors to “leave no trace,” the sheer number of people overwhelms employees when it comes to maintaining the park’s facilities. Additionally, many visitors have limited knowledge of “leave no trace” principles. This ignorance, whether willful or not, causes irreparable damage to Yosemite’s natural ecosystem and the services it provides for wildlife and humans.

Beyond physical litter, overcrowding disrupts the natural soundscape of Yosemite and other national parks. A soundscape is the accumulation of noise from all sources in an area, which, in a natural park, usually consists of biophony (noise generated by biotic factors) and geophony (noise generated by abiotic factors). With increased tourism, however, national parks have faced increased antrophony—the combination of human-generated and machine-generated noise. The sound of human voices, car engines, generators, music, air traffic, and more can be easily heard throughout the park. The anthropogenic impact on Yosemite’s soundscapes poses a threat to the survival of the park’s wildlife. Increased noise pollution disrupts animals’ feeding habits and breeding, as they become more preoccupied with the potential threat associated with the unusual noises than they are focused on subsistence.

Overcrowding also threatens the visitor experience. On the surface, increased pollution detracts from the experience of connecting with nature. On a more personal level, too, many visitors feel that the parks have fundamentally changed since overcrowding started to increase. One visitor said of their experience, “It’s still breathtaking now, but that sense of solitude is not as apparent any more.” The feelings of awe and wonder that normally accompany natural parks are diminished by the high concentration of people on trails and at popular destinations.

The issues developing in national parks like Yosemite can be largely attributed to advertising and social media. In 2016, the National Park Service launched a large-scale advertisement campaign to commemorate one hundred years since its creation. The campaign, aptly titled “Find Your Park,” was designed to connect people from around the world to America’s national parks and historic monuments, and it appears to have exceeded its goals. Visitation numbers have steadily increased in the years following the campaign’s launch, with one person saying, “the National Park Service’s ‘Find Your Park’ campaign was very successful (perhaps too successful) in encouraging people to visit national parks.” Federal marketing strategies such as this one have underestimated their influence on the public, boosting visitation numbers, but also accelerating the environmental degradation in the very parks being promoted. 

The visibly negative effects on national parks like Yosemite beg the question as to why more aggressive solutions are not currently being implemented. It has proven to be more difficult than previously thought to find a compromise that protects both the ecology of national parks as well as visitors’ enjoyment of them. In 2020, Congress passed the Great American Outdoors Act, which allocated up to $1.9 billion per year for five years to the National Park Service. The act focuses on constructing infrastructure, citing a “nearly $12 billion maintenance backlog” in national parks across the country. However, increasing infrastructure will correspondingly increase visitation and further worsen the initial problem, as wider roads and additional guest accommodations will only extend the capacity of a park and create a sort of urban sprawl. Worse, the act has no provisions for conservation or sustainability efforts, postponing any meaningful attempts to address the underlying problem at hand.

A reservation system is similarly ineffective in national parks. Most visitors and park service employees are against requiring reservations to visit national parks, with the belief that “it contradicts the founding premise that national parks were built for public benefit and enjoyment.” Preservation is not just a matter of saving the landscape of national parks, but of saving the ideas that these national parks were founded on. America’s national parks are symbolic of freedom and equal access to nature, making reservation systems a difficult solution to implement, regardless of how beneficial they could be.

Because national parks are severely underfunded, they depend on a stable source of income from large numbers of visitors. However, some alternative solutions have begun to minimize the damage caused by overcrowding without compromising the visitor experience. The Yosemite Area Regional Transportation System (YARTS), for example, has seen success in providing public transit in the national park as well as around the greater area. Public transportation reduces the number of cars congesting the park’s entrances, shortening car lines and minimizing the carbon footprint of its visitors. Similarly, the Zero Landfill Initiative has been successful in diverting a majority of Yosemite’s recyclable trash from landfills to recycling plants. Efforts like these, although few in number currently, are growing across the country, and together can change the future of national parks. The institutions maintaining Yosemite, as well as the park’s visitors, have the power to reimagine the use of the park as they once did at its conception.


Childers, M. (2021, June 1). Overcrowded US National Parks Need a Reservation System. The Conversation. Retrieved from 

Find Your Park. National Park Foundation. (2016). Retrieved from 

Golden, L. (2020, January). Yosemite Soundscape: An Assessment of Anthropogenic Noise in Tuolumne Meadows (thesis). ProQuest. Retrieved from 

Repanshek, K. (2021, January 1). 2nd Annual Threatened and Endangered Parks: Overcrowding and Visitor Management. National Parks Traveler. Retrieved from 

Robbins, J. (2017, July 31). How a Surge in Visitors is Overwhelming America’s National Parks. Yale E360. Retrieved from 

Tran, M. (2021, September 10). ‘It’s not sustainable’: Overcrowding is changing the soul of US national parks. The Guardian. Retrieved from 

U.S. Department of the Interior. (2020). Visitation Numbers. National Park Service. Retrieved from