Jill Livingston's: "That Ribbon Of Highway"

@ LA

Mike Ballard's Ridge Route Site

National Register of Historic Places --the ridge route is listed here

US 99 Side Trips: Piru Gorge and Gorman -- this has a little info

Santa Clarita Valley Historical Society

The Ridge Route Communities Historical Society and Museum

Don Wilson's Historic Hwy. 101 site

http://llatker.com

http://caltrafficsigns.com/ -- Pictures and info about historical traffic signs