What would a treasure legend be without maps?
Probably the earliest map that references a mine is seen above, it was drawn up by Stephen Austin in the late 1820’s. Just below the “Rio San Saba” there are the words “mina de plata”, Silver Mine. He had heard rumors of a mine, and silver mines sure would help draw people into Texas. There is no doubt that James Bowie and his brother Rezin Bowie saw this map before they went looking for the mine.
This next map was printed in 1841, the target audience was German immigrants. A good number of Germans moved to the Texas “Hill Country” in this era. Here the “old fort” is noted and the “Silver Mine” is on the other side of some mountains in the upper left hand corner. Again, it may have been designed to entice settlers to Texas. Note that there is no town of San Marcos yet–it did not exist until several years later. That goes against the story recounted by J. Frank Dobie and others that “Dixon” (one of the 1868 treasure hunters) was living in San Marcos in about 1840. A German naturalist toured the area around the old fort in the later 1840’s and noted that the land consisted of limestone, and minerals like silver in limestone would be without precedence.
The next map was from a a team of Spaniards, led by Nicolas de Lafora, who undertook a survey of all the frontier presidios north of Mexico in 1767. Due, in part, to that inspection the post was later officially abandoned. The Spanish officials believed that it served no purpose. The outline of the presidio matches the (partly) reconstructed presidio in Menard, TX. There are fences of some sort to the East and West that connect to the river. It was thought that horses were kept there. The remains of a smelter and at least 15 pounds of slag were found near the fort. That could have been from smelting silver, or maybe from testing samples. In 1937 the remains of an assay lab were found near the chapel, in the north-west corner. The irrigation canal is in the lower part of the map. The irrigation canal was dug to support the mission that existed to the south-east of the fort. It existed until it was destroyed by the natives less than year after it was founded.
The Spaniards kept livestock to the west, at least until the Comanche made stepping out of the presidio hazardous at all times. The area to the west has the most interesting treasure legend.