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Mountain Defense League Records

Identifier: MS-0410

Scope and Contents

The Mountain Defense League Records represents the administrative records of the Mountain Defense League (MDL) for its three decades existence, and the work of both Bryon Lindsley and Pandora Rose as former presidents of the MDL. The majority of the collection consists of records from a variety of federal, state, and private organizations including legal documents, legislation, newsletters, annotated maps, and publications.  The MDL worked in conjunction with several federal agencies, most notably the Department of the Interior, U.S. Department of Agriculture, U.S. Forest Service, and the Bureau of Land Management. The collection is divided into two major series: Administrative Files and Environmental Research Files. The Administrative Files series is divided into five subseries: General Office Files, Correspondence, Legal Files, San Diego Environmental Review Board, and Sierra Club, San Diego Chapter.  The Environmental Research Files series is divided into five sub-series: Local Environmental Projects, General Plans, National Forests, Soil Surveys, and Publications.

The Administrative Files document the work of the Mountain Defense league from its inception in 1973 to the conclusion of Lindsley's presidency in 2002. The series is arranged in five subseries. The subseries contain development and fundraising work, general administrative documents, and legal files. The series also includes a section on the San Diego chapter of the Sierra Club which Lindsley was a member.

The Environmental Research Files document project files and regional development areas focused on environmental impacts and studies. The series is divided into five subject-based sub-series. Also included is the documentation of the MDL's decision making process regarding its focus and project selection. The first sub-series, Local Environmental Projects, documents several environmental issues in San Diego county from the 1970s to early in the 21st century, and consists predominantly of Environment Impact Reports (EIR), Environmental Impact Statements (EIS), biological or environmental assessments, management plans, legal action files relating to a specific topic within the project files, and records of decision for a few of the EIRs. It is arranged in alphabetical order based on the subject of documents. The second sub-series, General Plans, contain sections of the San Diego County General Plan. This sub-series also contains EIRs and legal action files pertinent to a specific portion of the General Plan are arranged alphabetically. The third sub-series, National Forests, largely document the MDL's work regarding the four major national forests in and around San Diego County: Angeles, Cleveland, Los Padres, and San Bernardino. It is arranged alphabetically. The fourth sub-series, Soil Surveys, documents the potential development area's soil contents. It is arranged in numerical order corresponding to the map number listed on each soil survey map with the exception of the two volume bound text that precedes the maps in the sub-series arrangement. The fifth and final sub-series, Publications, document a wide range of conservation and environmental topics. Materials in this section include government documents, wildlife magazines, brochures, news articles, federal registers, a census of agriculture, and legislation.


  • Creation: 1972-2004


Conditions Governing Access

This collection is open for research.

Conditions Governing Use

The copyright interests in some or all of these materials have not been transferred to San Diego State University. Copyright resides with the creator(s) of materials contained in the collection or their heirs. The nature of archival collections is such that multiple creators are often applicable and copyright status may be difficult or even impossible to determine. In any case, the user must assume full responsibility for any use of the materials, including but not limited to, obtaining publication rights and copyright infringement. When requesting images from Special Collections & University Archives for publication, we require a signed agreement waiving San Diego State University of any liability in the event of a copyright violation.

Historical Note

Byron Lindsley Jr. founded the Mountain Defense League (MDL) in 1973 as a small, grassroots organization that worked in San Diego County to preserve and protect the natural environment from encroaching developers. In particular, disputes with developers at Middle Peak, Mt. Laguna, and Palomar Mountain were some of the MDL's most notable projects. During its early years, the MDL's efforts targeted the general public with campaigns and billboards. The league gathered eighty five thousand signatures in a petition to stop development in Middle Peak in the Cuyamacas. The goal of the MDL was not to stop development altogether, but to preserve the special and unique natural areas of San Diego for future generations. Pandora Rose became president of the MDL after Lindsley's death in February of 2003. Rose joined the league in 2001, and had become the assistant director by 2002. Under Rose's leadership, the MDL fought development of a new center at Mission Trails that did not require the park to set aside eighteen acres of undeveloped land. Rose also supported and campaigned with Senator Barbara Boxer (D-CA) to pass the California Wild Heritage Wilderness Act from 2002 until the bill's passage in 2006. Pandora Rose led the League until her death on January 30th, 2008.


33.92 Linear Feet

Language of Materials


Arrangement Note

I. Mountain Defense League Office Files, 1972-2004

    1. General Office Files, 1972-2002

    2. Correspondence, 1973-2002

    3. Legal Files, 1981-1994

    4. San Diego Environmental Review Board, 1975-1989

    5. Sierra Club, San Diego Chapter, 1973-2000

II. Environmental Research Files, 1973-2004

    1. Local Environmental Projects, 1978-2004

    2. General Plans, 1979-2002

    3. National Forests, 1990-2004

    4. Soil Surveys, 1973

    5. Publications, 1974-2003

Source of Acquisition

Pandora Rose

Accruals and Additions

2004-020, 2005-050

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Other Descriptive Information

Please note that this collection was formerly titled the Pandora Rose Environmental Activism Collection.

Mountain Defense League Records
Jeannie Higbee (Intern); Kim Schwenk
Description rules
Describing Archives: A Content Standard
Language of description
Script of description
Language of description note

Repository Details

Part of the Special Collections & University Archives Repository

5500 Campanile Dr. MC 8050
San Diego CA 92182-8050 US