Back in the Santa Fe days, most the intermediate signals were on bridges like this one along the Marceline Sub. With the changes and upgrades for the coming PTC, only a few intermediate bridges are left standing. 2 bridges are left between Ft. Madison and Argyle. Here a westbound Chicago, IL, to LA stack train blast under the unchanged bridge at MP 244, 10 miles west of Ft. Madison. At MP 244 things still look like they always have looked, but changes are not too far off down the road.