Loggy Bayou is a 17.3-mile-long (27.8 km) stream in northwestern Louisiana which connects with the Red River. Bistineau is the reservoir of , which flows 115 miles (185 km) southward from Nevada County, Arkansas, into Webster Parish. Loggy Bayou flows through south Bossier Parish, west of Ringgold, in a southerly direction through Bienville Parish, and into Red River Parish, where north of Coushatta it joins the Red River, a tributary of the Mississippi. At , the river has a mean annual discharge of 1,960 cubic feet per second.