Westbound and Down the Santa Fe. Shortly after summiting Glorieta Pass, Amtrak's Southwest Chief heads west through the southern tip of the Rocky Mountains. This region is known for colorful rock formations and steep, rugged terrain. In the less than 10 miles between Glorieta and Lamy, the westbound Chief will descend 1,000' in elevation (>2% average grade). These mountains were the location of a major battle in the American Civil War. Dubbed the "Gettysburg of the West", the Battle of Glorieta Pass played an important role in shaping the Southwest. The Confederate Army attempted to launch a decisive blow to the Union. If it were to be successful, the Confederate States could establish a supply chain and hold West Texas, New Mexico and Arizona. Over the three day battle in March of 1862, the Confederate Army initially pushed the Union into retreat. The Union, however, was able to destroy the Confederate supply chain. With their lifeline to the outside world cutoff, the Confederate soldiers were forced to retreat back to Texas and Confederate Arizona. This battle proved just how important a reliable supply chain could be. Less than 20 years later, the railroad would be built through these mountains.