Mako [ISO 639-3: wpc], a Sáliban language spoken along the Ventuari River in the Venezuelan Amazon, has been variably reported as (critically) endangered and threatened. These reports, however, are based on second-hand information and/or self-reported census data. In this article, I present a vitality assessment of Mako that relies on first-hand fieldwork data from 20 communities in the Middle Ventuari River area. The analysis of the data--collected through interviews, community censuses, and participant observation between 2012 and 2014--shows that the situation is not as dire as previously reported and that the language is very vital in its local context. I also show that the place of Mako in the regional and national contexts put it in a vulnerable position and that steps should be taken to ensure its presence in new domains of use. Methodologically, I show the importance--and argue in favor--of including data from long-term participant observation in analyses and reports of linguistic vitality because of the access this methodology provides to tacit knowledge about language use and attitudes. This work thus contributes both to our understanding of language vitality among the Mako communities and to discussions of best practices in language vitality assessments.