The first of the auto trail pages has been upload and it covers the Old Spanish Trail (http://www.americanroads.us/autotrails/oldspanishtrail.html).
I plan on expanding this greatly. The driving guide will begin soon. I have completed preliminary driving directions for all of former US 290 from San Antonio to the junction with US 80 east of Kent. I have discovered not only some old sections from 1931-33, but also some 1919 era roadbed. I did this using the following resources:
"Eastern Coastal Highway and Old Spanish Trail", ACSC, 1934.
Mohawk Hobbs Grade and Surface Guide "Old Spanish Trail."
Google maps and aerial photos.
Topographic maps (1:24000, 1:100000, 1:250000) via Topozone.
NGS benchmark descriptions via Geocaching.com
I also consulted old Automobile Blue Books from the 1920s, but these were not of much help in comparison to the ACSC maps.
I still want to check the route with Terrabrowser aerial photos. I want to post some detailed aerial overlays for some of the old sections with the evidence I have to prove they were old alignments.
For OST fans, also check out my US 80 maps, photos and driving guides for California (http://www.americanroads.us/ushighways/ushighway80CA.html)
Parsa