Welcome to the forum.
I would recommend looking at John Murphey's website. He no longer maintains it, but he's still active in promoting the OST. His email is on the bottom of the home page. Look at the pages for the states you want to drive. He can likely tell you about some interesting hotels along the way.Drive the OST
If you look at my virtual road trips and the galleries (like the one you linked to), that will also show you some interesting places to see. Keep in mind that the Gulf Coast area of the OST changed a lot during just a few years due to reroutings as bridges were built, replacing ferries.Florida road trip
, Florida galleryAlabama road trip
, Alabama galleryMississippi road trip
, Mississippi galleryLouisiana road trip
, Louisiana gallery
If you do take the OST, I'd recommend trying to follow the Mississippi River Scenic Highway
(MRSH) north to Iowa. This is one of the old auto trails on my To Do list. It dates to 1919. As far as I know, nobody has researched this route, but I could provide maps of the general route if you want to explore. It had several branches in the south, so you could leave the OST at Mobile, AL and follow the branch northwest to Clarksdale and Coahoma, Mississippi (to meet the main trail), or you could follow the OST all the way to New Orleans and follow the main path of the MRSH north to eastern Iowa.
An auto trail called the Glacier Trail
originally linked Glacier National Park in Montana with St. Louis. This highway was theoretically extended west to Washington State and southeast to the east Florida coast. I have one single map showing this longer version of the trail. It seems to be following the much more documented Bee Line Highway, which branched off the OST in Cottondale, FL, and went up through Alabama to Birmingham. There were then two branches, an east and a west, that both went to St. Louis to connect with the original route. The highway goes northwest in Missouri to head northwards in Iowa through Ottumwa, Oskaloosa, Grinnell, Marshalltown, Iowa Falls, and Mason City to Minnesota.
Here's a short web site
from Iowa DOT about this trail.