Duffy's Peak is a small but prominent hill near the Salt Fork Brazos River in Garza County, Texas, south and east of the Caprock Escarpment of the Llano Estacado. Rising less than 50 feet above the river, it stands out because of its isolated position and because erosion left a resistant sandstone cap protecting the ground beneath it as nearby sediments wore away. Surrounded by silt loams, mesquite, yucca, cacti, grasses, and intermittent waterways prone to flash floods after heavy rain, it became an important landmark for early surveyors. The peak is said to bear the name of a member of the original survey team who died nearby in the late 1870s.