St. Lawrence Island Yupik is an endangered language of the Bering Strait region. In this paper, we describe our work on Yupik jointly leveraging computational morphology and linguistic fieldwork, outlining the multilayer virtuous cycle that we continue to refine in our work to document and build tools for the language. After developing a preliminary morphological analyzer from an existing pedagogical grammar of Yupik, we used it to help analyze new word forms gathered through fieldwork. While in the field, we augmented the analyzer to include insights into the lexicon, phonology, and morphology of the language as they were gained during elicitation sessions and subsequent data analysis. The analyzer and other tools we have developed are improved by a corpus that continues to grow through our digitization and documentation efforts, and the computational tools in turn allow us to improve and speed those same efforts. Through this process, we have successfully identified previously undescribed lexical, morphological, and phonological processes in Yupik while simultaneously increasing the coverage of the morphological analyzer. Given the polysynthetic nature of Yupik, a high-coverage morphological analyzer is a necessary prerequisite for the development of other high-level computational tools that have been requested by the Yupik community.