On route to our spring break vacation, hubby made an innocent comment that really got me to thinking. He said, "You know, there's only one natural lake in Texas."
As for the one natural lake in Texas, that would be Caddo Lake. An earthquake and a log jam helped create the 25,000 acre body of water. Not only is it the only natural lake in Texas, but it's the only natural lake in the south. What does this mean to authors creating settings for their historical fictions? Be sure to look at the history of the lake or river you're including in your manuscript. Due to flooding from the Brazos River, state legistlature mandated dams in the 1930s and 40s. These dams created lakes. If you're writing a historical western set along the Brazos River, make sure your characters don't encounter any lakes prior to this time.
Weather plays a part in the changing topography as well. As you know we took a trip to Indianola so I could better visualize my setting. Because of the two hurricanes (the one in 1875 and the one in 1886), the coastline if different than what my characters would have enjoyed. For one, there's less land.