This article outlines the differences in goals, methods and results that variationist researchers may encounter when exploring and/or documenting a threatened language variety, and underscores special considerations and aspects of the research program that linguists must work to control for when working with endangered varieties of Western languages. In particular, it examines questions and strategies for dealing with sparse data for longitudinal studies; fewer speakers for stratified samples; the inverse relation between linguistic fluency and age; social network constraints in small speech communities; literacy-centric exercises in oral language communities; and larger project protocols designed for stable linguistic communities. Throughout the paper, the collection and analysis of Louisiana French liaison data from 1939, 1977, and 2010 provide an application of the proposed methods.