Mine Safety Appliances

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More

part of Yosemite National Park Roads and Bridges Recording Project, 1991; see HAER No. CA-117 for overview Significance: The longest vehicular tunnel in the western United States at the time of construction, th More