The semantics of determiners and determiner phrases (DPs) in Okanagan Salish is largely unknown, and apart from N. Mattina’s (2006) study of Moses-Columbian determiners, there are no other systematic investigations into the semantics of determiners for Southern Interior Salish languages. This paper increases our knowledge of Southern Interior determiners and also helps to clarify how they compare with determiners in Northern Interior Salish (Matthewson 1998) and Central Salish (Gillon 2006). It also contributes to our understanding of cross-linguistic semantic variation in determiner systems. The determiner iʔ is the only determiner in Upper Nicola Okanagan and is best analyzed as involving a choice function over a contextually restricted domain of individuals (Reinhart 1997 and Kratzer 1998). Referential strength is determined by the amount of contextual restriction and by whether the choice function selects a singular or plural individual. As such, iʔ may be analyzed as a pragmatically conditioned overt...