This paper reports on the design and implementation of a morphophonological analyzer for Lakota, a member of the Siouan language family. The initial motivation for this work was to support development of a precision implemented grammar for Lakota on the basis of the LinGO Grammar Matrix. A finite-state transducer (FST) was developed to adapt Lakota’s complex verbal morphology into a form directly usable as input to the Grammar Matrix-derived grammar. As the FST formalism can be applied in both directions, this approach also supports generative output of correct surface forms from the implemented grammar. This article describes the approach used to model Lakota verbal morphology using finite-state methods. It also discusses the results of developing a lexicon from existing text and evaluating its application to related but novel text. The analyzer presented here, along with its companion precision grammar, explores an approach that may have application in enabling machine translation for endangered and under-resourced languages.