I believe this is where the Santa Fe Trail crossed highway 56 at this location. You should be looking for a Santa Fe Trail limestone marker on the north side of the highway about 50 feet north of the edge of the highway,. Certain times of the year I can see where this marker might be diffucult to see because of the high vegetation can hide the marker. Anyhow good luck and happy caching.
Congratulations to neilanibal for FTF !