Technical Abstract: The presence of limestone among midden scatters associated with Grand Gulch phase (A.D. 200 to 400) Basketmaker II period habitation sites (Matson et al. 1988) on Cedar Mesa, southeastern Utah has suggested that these fragments are remnants of stone boiling activities that may have altered nutritional properties of maize (Matson 1991:7). Recent experimental evidence reveals that heating limestone from natural sources on Cedar Mesa to 600° C or higher produces calcination that, in combination with water, creates calcium hydroxide, or slaked lime. Nutritional data from adding the heated natural limestone to a maize and water mixture suggest that this early form of nixtamalization, or lime treatment, produces beneficial results when compared to maize that has simply been boiled. In experimental samples boiled with limestone, the levels of several essential amino acids - tryptophan, lysine, and methionine - are significantly higher than in the control set. As early Basketmaker II groups were largely dependent upon maize (Chisholm and Matson 1994; Coltrain et al. 2006; Matson and Chisholm 1991; Reed 2002:9), and the grain is nutritionally insufficient on its own (Mertz et al. 1970; Wacher 2003), higher levels of these amino acids may have been made available through nixtamalization.