Natural resources management (NRM) is complex and relies on decisions supported by evidence, including Western-based science (WBS) and Indigenous and local knowledge. However, it has been shown that there is a disconnect between WBS and its application, whereby managers often draw on non-empirical sources of information (i.e., intuition or advice from colleagues). This article focuses on the role of WBS in decisions made in management of rainbow trout (Oncorhynchus mykiss) in the province of British Columbia, Canada. We conducted open-ended interviews with NRM branches of Indigenous and parliamentary governments, as well as with nongovernmental stakeholder groups, to examine (a) sources of WBS consulted in decision-making and (b) barriers to accessing WBS by managers. We found that respondents involved with NRM relied on a diverse set of sources for WBS, seldom relying exclusively on one source. However, respondents relied more on internal sources (government databases) compared to external ones (peer-reviewed journal articles). We also found that respondents described WBS as valuable and generally accessible, yet barriers were identified with respect to the interface and organization of government grey data and literature, paywalls associated with peer-reviewed journals and articles, and institutional capacity, time, and support. We recommend strategies and tools to facilitate accessibility of WBS in support of bridging the knowledge-action divide, including increased publishing of open access data/articles, systematic reviews, use of knowledge brokers, specialized WBS training, and knowledge co-production. It is our hope that identification of barriers and the implementation of improved access to WBS will result in more effective NRM by giving managers access to the tools and knowledge they need for evidence-based decision-making.