SECO CREEK. Seco Creek rises five miles north of Sentry Mountain and Farm Road 470 in southwestern Bandera County (at 29°44' N, 99°25' W) and runs southeast for sixty-six miles to its mouth on Hondo Creek, seven miles west of Moore in Frio County (at 29°02' N, 99°08' W). Seco, the Spanish word for "dry," was the name given the creek by Capt. Alonso De León, governor of Coahuila, who led an expedition that crossed the creek in 1689. At the creek's source steep to gently sloping terrain is surfaced by soils of variable permeability that support sparse scrub brush and grasses; the lower portion of the creek runs through flat terrain with intermittent shallow depressions surfaced by expansive clays that support water-tolerant hardwoods, conifers, and grasses.