[PRCo] Pennsylvania Sanborn Maps

[Stephen Titchenal]

I am looking for additional sources of maps of Pennsylvania Towns that may
show interurban/trolley routes through smaller towns. Sanborn Fire Insurance
Maps can sometimes be helpful. They were originally done for the insurance
industry and mapped businesses and towns using color to indicate building
type (brick, wood, etc). 

In Ohio anyone with a library card can search the commercial Proquest
collection digitized from Microfilm (B&W). A few libraries in the Pittsburgh
area appear to have local subscriptions to the online scanned microfilm set
of Pennsylvania towns or the original microfilm collection (73 reels)
Sanborn fire insurance maps. Pennsylvania [microform]
Publish Info 	Teaneck, N.J. : Chadwyck-Healey, 1983

Penn State at State College has a few areas scanned in color (basically
towns beginning with "A").
http://www.libraries.psu.edu/psul/digital.html#row1

The Library of Congress has a significant collection, but very little is
available digitally yet.
http://www.loc.gov/rr/geogmap/sanborn/index.php

Can anyone recommend the best library to view the Pennsylvania Sanborn maps
either online or using microfilm? Or are original maps available someplace
closer than State College or the Library of Congress?

Here is a link to an older union list of Pennsylvania Sanborn Maps. 
http://www.lib.berkeley.edu/EART/sanbul_PA.html
The US Census Bureau, Jeffersonville, IN collection appears to be at the
Library of Congress now. The Library of Congress has their own database of
Sanborn maps but unfortunately they have only a few Pennsylvania maps
online. (none for the Pittsburgh area).
http://www.loc.gov/rr/geogmap/sanborn/index.php

FYI, here is my compilation of Pittsburgh area online resources that I am
already aware of (many sources provided by list members -thanks):
Historic aerial photos (1937-1942, 1957-1962, 1967-1972)
http://www.pennpilot.psu.edu/
Pittsburgh Historic Maps http://digital.library.pitt.edu/maps/
Historic County Maps PennDOT
http://www.dot.state.pa.us/internet/bureaus/pdplanres.nsf/infoBPRHistoricCou
ntyMaps
Pennsylvania early 20th Century 7.5' Topos (300dpi at Penn State - 200dpi at
Maptech)
http://www.libraries.psu.edu/psul/digital.html#row1
http://historical.maptech.com/ (many originally scanned by list member
Derrick Brashear) 
The 200dpi Maptech scans were stitched together and georeferenced and
available at
ftp://www.pasda.psu.edu/pub/pasda/maptech_historic/

Library of Congress Panoramic Maps from the late 19th Century and early 20th
Century
http://lcweb2.loc.gov/ammem/gmdhtml/citymapPlaces11.html
http://lcweb2.loc.gov/ammem/gmdhtml/citymapPlaces12.html
http://lcweb2.loc.gov/ammem/gmdhtml/citymapPlaces13.html


Stephen Titchenal
www.railsandtrails.com
www.titchenal.com