Abstract Impact evaluation design and implementation require technical and methodological skills and funding. If the interest is in bridging the research–practice gap and mainstreaming its recommendations into decision‐making, then impact evaluations will require collaboration among researchers, practitioners, and funders. In 2020, Switzerland began applying impact evaluations to assess conservation and sustainable development outcomes in Swiss parks of national importance. Four years later, we count four impact evaluations on park effects. While three studies focus on the park effect on ecological compensation areas, turnover/business efficiency, direct payments, and farm income, one study compares the effect of park status on perceived landscape quality. Plans to design and implement further studies exploring the park effect are underway. In this paper, we present the main opportunities and challenges encountered during the design and implementation of these evaluations. Against this background, we emphasize that collaboration is key to mainstreaming impact evaluation into practice. This paper offers suggestions for fostering such collaboration across various stages of the impact evaluation process, including technical capacity, data collection, and funding.