On January 27, 1807, U.S. Army Lt. Zebulon Pike and nine soldiers, whom Pike affectionately called his "Dam'd Set of Rascals," crossed the Sangre de Cristo Mountains over Medano Pass into the territory of New Spain on a reconnaissance mission ordered by his commander to examine the Spanish borders of the Province of New Mexico. After a severe day's march that required a steep ascent through three feet of snow while carrying heavy packs, they made camp in the first timber they found. The next day they discovered the San Luis Valley and camped at the foot of the Great Sand Dunes. On January 29, just before reaching Zapata Creek and camp, Pike and his men paused to look back and silently reflect on their ordeal and accomplishment as they took in the snow-filled pass, the unexpected sand dunes, and the immense valley bounded by a jagged mountain crest.