Hello, people of KQED. We’ve got some hard ones for you below! Over 400 of you helped place these Sanborn maps last month, and now we’re down to the difficult ones: burned pages, streets that no longer exist, and pages with more than one map on them. Dig in and join the fun!
—Michal Migurski, August 16.

Help add some geography back to the famous 1905 Sanborn Insurance Atlas!

Thanks to the combined efforts of the San Francisco History Center and the David Rumsey Map Collection, this historic glimpse of San Francisco in the years leading up to the devastating 1906 earthquake is now available in full color. Created for fire insurance purposes, it includes precise detail on every building in city limits, including its use and construction. Did you know there was a skating rink on Mission across from The Sycamore? Or that City Hall used to be across the street from its current block?

John at Burrito Justice says: “At some point I will make a mapesque clickable HTML grid … Imagine an iPhone app where you could stand on a corner and pull up the Sanborn map to see what was there. You turn around, and the map rotates with you. Awesome, no?” The first step to creating a map of every atlas page is getting them roughly matched up to the current geography, and we’d like your help. Can you spend a few minutes aligning pages of the atlas with a map from today?

Here’s everything that’s been placed so far:

700 of 700 pages matched and 616 pages confirmed so far!

Maptcha is a thing by Michal Migurski, with extensive input from George Oates and a group of early testers, and encouragement from John.

Tell us what you think.
Road map data CC-BY-SA OpenStreetMap Contributors, Cartography ©2011 GeoIQ