<p>Cottage Grove Reservoir is located downstream from the Black Butte Mine Superfund Site in Oregon, USA, where mercury was mined for approximately 70 years. The reservoir is impaired due to elevated fish tissue mercury concentrations. The effectiveness of posted fish consumption warnings is unknown. Therefore, the goal of this study was to address this knowledge gap through a population-based survey of adult female licensed recreational fishers (<i>n</i> = 5000). Associations between awareness of fish consumption warnings and participant characteristics were investigated using logistic regression. A total of 391/5000 (7.8%) female fishers completed the survey, including 35/391 (9%) who fished at Cottage Grove Reservoir, the most popular fishing location, despite the legacy of mercury contamination from Black Butte Mine. Among those who reported which fish they caught and ate from Cottage Grove Reservoir, most fishers complied with posted fish consumption warnings, but not all. Moreover, a small percentage of women reported fishing at multiple mercury-contaminated locations. Younger age (18–30 years), those with lower annual household incomes (&lt;$25,000), and those with less education (high school or less) had lower odds of awareness of fish consumption warnings. The results identified gaps between awareness of fish consumption warnings and fishing activities, and the need for increased outreach activities targeting vulnerable groups.</p>