Four in 10 oil and gas wells drilled between fiscal years 2009 and 2012 escaped federal inspection even though they are near national forests, fragile watersheds or otherwise identified as higher pollution risks. Here are the states with wells on federal or Indian lands that were deemed "higher priority" for drilling inspection by the Bureau of Land Management, and the number that were not checked:

State Number of high-priority wells Number of high-priority wells uninspected
Alabama 1 0
Alaska 5 1
Arkansas 13 5
California 99 31
Colorado 420 244
Louisiana 7 3
Michigan 1 0
Mississippi 4 0
Montana 144 25
New Mexico 342 121
New York 2 0
North Dakota 696 116
Ohio 1 0
Oklahoma 5 1
Pennsylvania 6 1
South Dakota 2 1
Texas 1 0
Utah 327 219
Wyoming 1410 632

Source: Bureau of Land Management and Associated Press analysis