Snow droughts, deluge, and reservation systems interact to drive recreation access at Yosemite National Park

Abstract

Changes in snow extremes can have important but as yet underexplored impacts on the 1.2-trillion dollar outdoor recreation industry, impacting essential ecosystem services. These hydroclimate conditions interact with reservation systems used by park managers to manage potential impacts to park resources and visitor experiences. Climate change extremes and associated hazards limit and enable access in different ways: snowpack from extreme wet years can prolong road closures at higher elevations, while extreme snow drought enables early season access. Few studies have attempted to assess and compare the influence of snow conditions and reservation systems among a population of visitors, as we do at Yosemite National Park. Roads were still closed into the 2023 peak season from a record extreme snow deluge, yet entry was unrestricted due to lack of a parkwide day use reservation system. This combination led to higher overall visitation levels but spatially constrained visitor mobility and resulted in more crowded conditions and traffic congestion. We assess the efficacy of the day use reservation system in limiting use by comparing differences from the annual mean and monthly volume and timing of visitors. Results show that annual use levels are influenced more by managed access than by climate extremes, and that results differ by overnight use types and traffic count locations with seasonal access limitations. These results demonstrate a novel aspect of the impacts of changing climate extremes with human use of natural resources and suggest that appropriately managed reservation systems are an essential tool for managing recreation resources in a changing climate.

Keywords: Climate extreme; Outdoor recreation; Snow deluge; Snow water equivalent; Use limits; Visitor use management.

Fig. 1

People-at-one-time visitor monitoring counts for 2023 and 2024 at popular viewing areas and trail segments. Asterisks denote viewing locations that are directly dependent on water features.

Fig. 2

Mean daily discharge (ft³/s) of Merced River at Pohono Bridge, 1917–2022 versus 2023, gauge no. 11266500.

Fig. 3

(a) Percent of average April 1 SWE for Tuolumne Meadows snow course, and (b) Tioga Road opening day of year by April 1 SWE. Snow drought years (25th percentile is 62% of average) are shown with red, high snowpack years (75th percentile is 135% of average) are shown with blue, and near average snowpack years (62–135%) are shown with gray. Dashed lines show a running average of 2 years, chosen to account for antecedent conditions of the previous season and visualize variability over time.

Fig. 4

Yosemite NP with year-round and seasonal roads and locations. The upper inset shows locations of people-at-one-time monitoring in Yosemite Valley. Map by author, data source: Esri, World Hill Shade [basemap], World Topographic Map (accessed 2025). ArcGIS Pro: Version 3.3.

Fig. 5

April 1 SWE data from three snow courses closest to major visitor locations in Yosemite. PGM = Peregoy Meadows, TUM = Tuolumne Meadows, GFL = Gin Flat. Lines indicate linear regression slopes (conditional mean) for each station, with April 1 SWE estimated as a linear function of water year.

Fig. 6

Percent difference from annual mean of visitation (1980–2024) for overall park-wide visitation, types of overnight use, and vehicle traffic counts for year-round entrances and seasonally accessible locations by recent managed access status and by climate conditions. Asterisks indicate statistical significance (CI 95%).

Fig. 7

Yosemite National Park monthly visits by reservation policy. Reservations (2020, 2021, 2022 & 2024) and no entry limits (2023).

Fig. 8

Average monthly park-wide visitation to Yosemite NP by climate conditions and managed access status.

Fig. 9

Average monthly overnight use at Yosemite NP (1980–2023) by climate conditions and managed access status for concessionaire lodging, tent campers, RV campers, and backcountry camping.

Fig. 10

Average monthly vehicle counts at Yosemite NP (1985–2024) by climate conditions and managed access status for year-round entrance stations.

Fig. 11

Average monthly vehicle counts at Yosemite NP (1985–2024) by climate conditions and managed access status for locations with seasonal access limitations.