Dagle joined Pacific Northwest National Laboratory (PNNL) in 1989, and currently manages several projects in the areas of transmission reliability and resilience for the Department of Energy (DOE) Office of Electricity and other clients. Recent project highlights include leading the North American SynchroPhasor Initiative; serving on the leadership team of the Department of Energy's Grid Modernization Laboratory Consortium; leading the team that provides cybersecurity reviews for the DOE Smart Grid Investment Grants and Smart Grid Demonstration projects associated with the American Recovery and Reinvestment Act of 2009; and co-leading the PNNL Future Power Grid Initiative from 2010 to 2015. In 2014, Dagle was invited to serve on a National Academy committee to provide recommendations for the analytical research foundations for the next-generation electric grid. In 2016, he was invited to serve on another National Academy committee focused on enhancing the resilience of the United States’ electricity system. And in 2019, he was invited to serve on a third National Academies study committee on the future of electric power in the United States. In 2018, Dagle was named co-director of the Advanced Grid Institute, a joint institute with Washington State University. Other career accomplishments include leading the data requests and management task for the United States-Canada Power System Outage Task Force investigation of the August 14, 2003 blackout; supporting the DOE Infrastructure Security and Energy Restoration Division with on-site assessments in New Orleans following Hurricane Katrina in 2005; and serving as a member of the National Infrastructure Advisory Council study group that was formed in 2010 to establish critical infrastructure resilience goals.