This book examines the distribution of Blackfoot /s/, which differs from that of all other consonants. Clusters of more than two consonants occur only with /s/, and clusters of more than three consonants occur only with geminate /ss/. The Blackfoot syllable seems to be overwhelmingly simple, with /ss/ clusters being the only outliers. While all other geminates occur between vowels, geminate /ss/ often occurs before, after, or between other consonants. This book describes the distribution of /s/ in Blackfoot, and then proposes that this distribution can be accounted for by positing that /s/ is inherently moraic in Blackfoot, a claim usually reserved only for vowel segments. This book also proposes that because of this inherent moraicity, /s/ can act as a syllable nucleus in Blackfoot. Finally, these claims are examined within the framework of Optimality Theory.