Visitor Experience and Resource Protection: A Framework for Managing the Carrying Capacity of National Parks

Abstract

Carrying capacity is a perennial issue in the administration of parks and outdoor recreation. In its most generic form, carrying capacity refers to the amount and type of use that can be accommodated in parks and related areas without unacceptable impacts to park resources and/or the quality of the visitor experience. Carrying capacity is an increasingly important issue in the national park system, which now receives nearly 300 million visits annually. Research on carrying capacity suggests that it can be defined and managed through formulation of indicators and standards of quality. Indicators of quality are measurable, manageable variables that define the quality of visitor experiences and natural/cultural resources. Standards of quality define the minimum acceptable condition of indicator variables. Once indicators and standards of quality have been formulated, indicator variables are monitored, and management action is undertaken to maintain standards of quality. This approach to carrying capacity is central to contemporary park and outdoor recreation planning frameworks, including Limits of Acceptable Change and Visitor Impact Management. This approach has been incorporated in Visitor Experience and Resource Protection (VERP), a framework designed by the National Park Service to manage carrying capacity in the national park system.

VERP has been applied over the past decade to an expanding diversity of areas in the national park system. Those applications have relied on a program of social and natural science research that has provided information to help formulate indicators and standards of quality. Examples of such indicators and standards include the number of people at one time at attraction sites, and the amount of impact from off-trail hiking at Arches National Park; amount of crowding and conflict on the carriage roads of Acadia National Park; maximum number of people at one time in an historic building in Golden Gate National Recreation Area; maximum waiting times at Statue of Liberty National Monument; persons per viewscape on trails at Grand Canyon National Park; number of boats seen on the Colorado and Green Rivers in Canyonlands National Park; number of snowmobiles encountered in Yellowstone National Park; and number of people at one time along trails and at attraction sites in Yosemite National Park. VERP is a structured framework within which to conduct a systematic, thoughtful, traceable, and defensible analysis of carrying capacity, and provides the National Park Service with a “program that works” to manage the carrying capacity of the national park system.