The search for oil in southeast Wyoming has set off a massive seismic survey effort. Last fall, three seismic surveys alone blanketed an area 1,500 square miles in Laramie and Converse counties. That’s an area almost half the size of Yellowstone, or 50 percent larger than the state of Rhode Island. These are some of the largest surveys ever seen in Wyoming, according to state officials. Initial drilling hasn’t struck upon another bonanza field like the Bakken oil field in North Dakota or the Jonah natural gas field in western Wyoming. But with a comprehensive mapping of the area’s geology, oil developers hope to improve their ratio of success.