Morley graduated with an A.B. in American Research from Harvard in 1907. His first field trip to Mexico and Yucatán was in January of the same year, when he visited and explored several Maya sites, including Acanceh, Xtocche, Labna, Kabah, Uxmal, Zayil, Kiuic, and Mayapan. He spent several weeks at Chichen Itza as a guest of Edward Thompson, where he assisted with the dredging of the Cenote Sagrado. On his return trip to the US he carried with him artifacts taken from the cenote, to be deposited at Harvard's Peabody Museum.