...r northward, threatening the roads to Chattanooga. Buckner was next north of Polk; then Walker's corps; and the extreme north of the Confederate line was Bushrod Johnson's division near Ringgold. Rosecrans was made aware of these dispositions to some extent by cavalry skirmishing near Reed's bridge, and observing that his left was about to be enveloped, he ordered Crittenden to form on the Rossville ro...