Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Ninth Street Bridge, Spanning Allegheny River a...
Survey number: HAER PA-490-C Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000019
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Seventh Street Bridge, Spanning Allegheny River...
Survey number: HAER PA-490-B Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000018
Three Sisters Bridges, Seventh Street Bridge, Spanning Allegheny River...
Survey number: HAER PA-490-B Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000018
Three Sisters Bridges, Ninth Street Bridge, Spanning Allegheny River a...
Survey number: HAER PA-490-C Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000019
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Seventh Street Bridge, Spanning Allegheny River...
Survey number: HAER PA-490-B Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000018
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Ninth Street Bridge, Spanning Allegheny River a...
Survey number: HAER PA-490-C Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000019
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Seventh Street Bridge, Spanning Allegheny River...
Survey number: HAER PA-490-B Building/structure dates: 1924-1926 Initial Construction National Register of Historic Places NRIS Number: 86000018
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More
Three Sisters Bridges, Sixth Street Bridge, Spanning Allegheny River a...
Significance: The Three Sisters Bridges represent an adaptive engineering design response to political and technical concerns. County engineers successfully maneuvered around federally-mandated clearances, aest... More