This is the location where the Glanton Gang controls a River Ferry, robbing and killing those who take it. The gang also sets their base here. 

Where the Glanton Gang Regroups after being hunted by the Mexican Army

The Glanton Gang at this point had discovered and massacred a group of Gilenos (Apache Native Americans in the eastern Chihuahua Area) this occurs at a lake at this location

This area is likely where the Glanton Gang first Encountered the Apache Native Americans 

The book tells that The Kid was born and raised in a poor rural home in Tennessee, not very specific as to where the home is in Tennessee. 

This is a very significant/recurring location in the story. The Kid after escaping the massacre of Captain White's regiment, the kid is arrested by Mexican authorities and is held prisoner in Chihuahua City, until he is freed and joins the Glanton Gang. The rest of the novel involves the Glanton Gang getting bounty contracts and returning to Chihuahua City to cash in their collected scalps and afterward celebrating, repeating the process until they are chased out of Mexico.

This is where Captain White's US army regiment was attacked by a Camanche tribe, massacring most of the men, the Kid manages to escape.

Where the Comanche attack occurred that destroyed Captain White's army regiment 

Where the Kid was recruited in 1849