ABSTRACT1. Species reintroductions are an increasingly fashionable tool among conservation practitioners for restoring locally and nationally extinct populations. For a reintroduction programme to be successful, an understanding of the causes of the decline of a species is required. This, however, proves challenging when baseline data on the distribution and abundance of the species are limited.2. This paper uses evidence from historical literature to map the former distribution of the burbot (Lota lota) within UK rivers before its extinction in the early 1970s. A scoring system was developed to model anecdotal descriptions of burbot abundance from the collected literature.3. The former distribution was divided into four geographical areas based loosely on catchment boundaries. The literature identifies 42 rivers in eastern England in which the burbot was likely to have existed. The status of the species in the Thames catchment is still unclear as information from written sources is contradicted by evidence from the archaeological record.4. The findings indicate that the year of source data was a significant predictor of burbot abundance across the former population as a whole and for three of the four geographical areas (the Trent catchment, the Fenland rivers and the Yorkshire rivers). The timing of the burbot's decline showed differences between the geographical regions, with the Trent catchment exhibiting an earlier decline than the Fenland and Yorkshire areas.