InsideClimate: The oil that erupted in the town of Mayflower back in March began its trip in an Illinois hamlet named Patoka, 90 minutes east of St. Louis. It shot down ExxonMobil's 20-inch Pegasus pipeline, under farms and forests, over the Mississippi River via a state highway bridge, through the Missouri Ozarks, across the Arkansas state line and, a few miles later, near the workplace of one Glenda Jones, whom you can find on a summer Saturday at her bar job, watching the Cardinals thump the Cubs. The other...