Encroachment on Military Bases Prevention Act

Encroachment on Military Bases Prevention Act - Amends the Endangered Species Act to prohibit the Secretary of the Interior (Secretary) from designating as critical habitat any lands or areas owned and controlled by the Department of Defense, or designated for its use, that are subject to an integrated natural resources management plan under the Sikes Act if the Secretary determines that such plan addresses special management considerations or protection. Requires the Secretary to consider impact on national security when making critical habitat determinations.

Amends the Act commonly known as the National Park System General Authorities Act to require: (1) the Secretary to notify the Secretary of Defense of the exact military lands included in any study of an area for potential inclusion in the National Park System (NPS); and (2) the Secretary of Defense to evaluate the existing environmental protections for such lands and the importance of such lands to military readiness and preparation. Authorizes the Secretary of Defense to require the Secretary to exclude such lands if it is determined that current environmental protections are adequate and that their inclusion in the NPS would adversely affect military readiness and preparation.

Amends the National Marine Sanctuary Act to prohibit the Secretary from including as a national marine sanctuary any area that the Secretary of Defense has designated for use for military readiness activities.