The Idaho Eastern Railroad (IERR), "The Snake River Route", has 268 miles of former Union Pacific trackage in southeastern Idaho. They began operation in 1993 under the management of Watco, Inc. (WAMX). Their primary tonnage is agricultural products.

IERR 3504 at Twin Falls, ID, 8/06/02.  Note the unique
 spark arrestor on the exhaust stack.

IERR 3505 at Twin Falls, ID, 8/06/02.

IERR 3006 at Twin Falls, ID, 8/06/02.