With regard to the March 10 Yucatan article on the Kukulcan pyramid of Chichen Itza, Sherrie Strausfogel's ethnological description of the archeological tourists that flock to witness the vernal and autumnal equinox phenomena is incorrect. The equinox phenomena at Chichen Itza has been known to those tourists since the early 1970s. Gringos, identified by the Maya as the Chachacmac, are not only the people most informed about the phenomena, they rediscovered it. The little knowledge modern Mayan descendants have of the phenomena has been derived from gringos and popular Yucatecan tourist guidebooks. . . .