Reviewing the Configuration and Extent of the Midcontinent Rift System

•Limited data results in different mapped locations of the MRS.•MRS extends across the Grenville Front in SE Michigan to the Canadian border, but not south into Ohio and beyond.•Grenville overthrusts may have overrode the southeast terminus of the MRS.•Unambiguous geophysical and geologic evidence does not support extension of the rift south of Kansas or Michigan.•Mapping the “Fort Wayne Rift” anomalies as a part of the rift system is problematic.