NPS Photo/Lou Sian

A couple strolls through Cathedral Grove on a quiet morning in winter when visitation is typically low. Signage at the entrance to this area reminds visitors that they are in a quiet zone.

NATIONAL PARKS ARE MANAGED to protect the environmental and experiential values of the landscapes they represent. As the nation continues to grow into a more populous, developed, and noisy place, these values have expanded from landscapes to “soundscapes” and include the natural and cultural sounds of national parks. In fact, sounds have been identified by the National Park Service (NPS) as a resource that must be protected. In doing so, the National Park Service is challenged to define “soundscapes,” understand the effects of noise on visitors and wildlife, and take appropriate management action when necessary.

Management of environmental and experiential impacts on national parks is increasingly guided by management-by-objectives frameworks such as the NPS Visitor Experience and Resource Protection (VERP) framework (NPS 1997; Manning 2001; Manning 2007). Like other such frameworks, VERP has three principal steps. First, indicators and standards of quality are formulated. Indicators are measurable, manageable variables that help define and quantify desired resource and social conditions. Standards of quality define the minimum acceptable condition of indicator variables. Second, indicators of quality are monitored over time. Third, management actions are taken to help ensure that standards of quality are maintained. With continued monitoring, VERP is an iterative or “adaptive” process, providing feedback that informs management about the degree to which management objectives are attained and the efficacy of management actions taken. This article describes a program of research designed to support application of VERP and management of visitor-caused noise at Muir Woods National Monument (Muir Woods) in California.