This paper presents a Universal Dependencies (UD) treebank of Gwich’in, a severely endangered Athabascan language. The treebank, developed using instructional materials and dictionaries, includes 313 annotated sentences. This paper discusses the methodology used to construct the treebank, the linguistic challenges faced, and the implications of annotating a polysynthetic, morphologically complex language within the Universal Dependencies framework. The treebank was released with UD version 2.15 and available at https://github.com/UniversalDependencies/UD_Gwichin-TueCL/.