At Kozlowski's, Slough and Chivington decided on their plan of attack. Slough would take about 2/3rd of th trooopps' including all the artillery, down the pass toward Santa Fe. Chivington would take his battalion of 113, guided by Lt. Col. J. Francisco Chaves of the New Mexico Volunteers over the shoulder of Glorieta Mesa and fall upon the Confederate flank. The plan was set in motion on the morning of the 28th.

Scurry had decided not to wait at Apache Canyon. He started almost all of his force, including Pyron's men, eastward through the pass. He left his supply wagons with a small guard at Johnson's Ranch at the junction of Glorieta pass and Apache Canyon. Around mid morning he hit Slough's lead elements near Pigeon's Ranch, located on the Santa Fe Trail. Scurry deployed his men in a long line and set his artillery up on a low hill. Slough did the same though his line was shorter than Scurry's, he having about 300 fewer men.

Scurry's battalions attacked with great vigor but were met with equal vigor by teh Coloradans. Slough's position was not strong, but the attack was stopped long enough to give his men time to fall back to a better one. Slough tried to send men to his right around Scurry's flank but a detachment of Texans met his men head on and stopped them. Scurry kept pressure on Slough's line while organizing his own force in a three pronged assault. Late in the afternoon the Confederates attacked Slough's entire front driving in the flanks and threatening the center. The outnumbered Federal infantry held the Texans at bay long enough for the artillery to pull back to a third line. Scurry's men pursued, but were exhausted from the six hour battle. Slough soon abandoned this line leaving the Confederates in undisputed possession of the field.

While all this was going on at Pigeon's Ranch Chivington had completely missed Scurry's flank falling instead on the Confederate suppply train parked at Apache Canyon. Lightly guarded the train was captured and destroyed leaving Scurry with no ammunition, food blankets, or other supplies. Chivington returned to Kozlowski's and Slough's reunited command continued in withdrawal toward Ft. Union. Unbable to sustain his men in the fieldScurry was forced to go back to Santa Fe where Sibley joined him.

Canby had left Ft. Craig early in April and had come north threatening Albuquerque and drawing Sibley's entire force back from Santa Fe. Canby and Slough united their forces east of the Sandia Mountains and now outnumbered the Texans. Sibley faced with superior numbers and even more destitute than before knew that to stay and fight would mean destruction of his brigade. He decided to retreat from New Mexico. The Confederacy never again seriously threatened the far west.