As a result of the 1975 Moodus Conference, a task force was established to analyze the ozone data from the 19 Moodus states and to assess the importance of ozone transport across the Midwestern and Northeastern United States. Data from daily ozone maps, aerial ozone measurements, and trajectory analysis are used in this paper to describe the typical summertime ozone episode in the Moodus study area. The results indicate that ozone concentrations in a high pressure system as it moves out of Canada into the Midwest are typically 30–50 ppb. Higher concentrations first develop over the areas of high anthropogenic percursor emissions. As the high pressure moves eastward, the areas of high ozone increase in size and concentration and eventually merge together. Verticle ozone profiles conducted on consecutive days and nights suggest an ozone half‐life of 46.8 h above the nocturnal inversion layer. Using the corresponding dark phase rate of ozone decay in conjunction with air parcel trajectories, it was estimated that, under certain conditions, over 100 ppb of ozone are transported from the Midwest to the Northeastern Atlantic Coast.