From late October to mid-November 1846, the Mormon Battalion marched south following the Rio Grande. On Nov. 13, its members said goodbye to the river and headed southwest toward what is now the borders of Mexico, Arizona and New Mexico. The approximate site of where they separated from the river is Hatch, Doña Ana County, N.M.
Because this was wilderness with no roads or trails, determining which specific route to take was very challenging. They had to maintain the general direction while avoiding mountain ranges that were difficult to pass over. Scouts also had to look for water sources that could supply a vast group the size of the battalion.
By this time, three sick detachments had been sent to Colorado, leaving the number of traveling battalion members at about 335.