It was attested in a notebook titled Mots loups (literally translating to "wolf words"), compiled by Jean-Claude Mathevet, a priest who worked among Algonquian peoples, composing of 124 pages.
Loup A, which is likely the language of the Nipmuck,[2] is principally attested from a word list recorded from refugees by the St. Francis mission to the Abenaki in Quebec.
This may not be a distinct language, but just notes on the speech of various New England Algonquian refugees in French missions.
[3] According to Gustafson 2000, the geographical location and phonology of Loup rule out association with any other tribes except for the Nipmuck.
[1]The phonology of Loup A (Nipmuck), reconstructed by Gustafson 2000: The vowel sounds likely have the same phonetic quality as other southern New England Algonquian languages.