 The exit was closed and removed as a result of the department of transportation's efforts to move traffic away from a potential crash site at the end of the Ellsworth AFB runway.The partial cloverleaf interchange of exit 66 was also demolished shortly thereafter.Exit 67, which was constructed not too long before the closure of exit 66, is now used as the main entrance and exit feeder to the base, and it is less likely to be impacted by a potential crash.