HIDALGO FALLS. The Hidalgo Falls are on the Brazos River five
miles northwest of Washington-on-the-Brazos in Washington County
(at 30°24' N, 96°11' W). The Hidalgo Cliffs rise above the
falls, twenty feet above river level. They are surrounded by
rolling hills that support post oak forest. The falls are a
series of exposed limestone shoals that were formed by the
erosion of the adjacent Hidalgo escarpment. They mark the
dividing line between the middle and upper reaches of the Brazos
River. Riverboats headed above Hidalgo Falls had to wait for a
rise in the water level before proceeding upstream; if a boat's
navigator misjudged the length of time the river would remain
above normal level, the riverboat was trapped above the falls
until the river rose again. The Brazos River above the falls
offered limited access to upriver points during most of the
year. Pamela A. Puryear and Nath Winfield, Jr., Sandbars and
Sternwheelers: Steam Navigation on the Brazos (College Station:
Texas A&M University Press, 1976). The