Middle Tennessee is a distinct portion of the state of Tennessee, delineated according to state law as the 41 counties in the Middle Grand Division of Tennessee. According to custom, Middle Tennessee consists of that portion of the state east of the Tennessee River's western crossing of the state (in which it flows northward back into Tennessee after having flowed through northern Alabama) and west of the dividing line between the Eastern and Central time zones. Exceptions to this rule are that Hardin County, which is located on both sides of the Tennessee River, is considered to be entirely in West Tennessee and that Bledsoe, Cumberland, and Marion counties are generally considered to be in East Tennessee despite being in the Central Time Zone.