As the federal air quality standards get stricter and oil and gas production in upwind states and Canada rapidly expand, downwind states like Minnesota will face more challenges in future ozone air quality management. The contribution of ozone sources outside the state (transported ozone) versus the contribution of local sources to the ozone levels in Minnesota was evaluated. Focusing on the summer of 2011, a combination of field observations and model experiments was used to quantify the amount of ozone from local pollution sources that may be regulated by air quality management as opposed to the amount from natural background and from long-range transport. Emission sources outside the state exert a significant influence on Minnesota's air quality. Local sources and cross-state transport each contribute ∼ 25% of the simulated summer ozone. This is an abstract of a paper presented at the AWMA's 107th Annual Conference & Exhibition (Long Beach, CA 6/24-27/2014).