A wheel lift assembly lockout mechanism for an agricultural mower having a lift cylinder for moving the mower frame between raised and lowered positions. The lockout mechanism is positioned adjacent to a rod end of a lift cylinder and is pivotable between generally opposing lockout and free positions. First and second stops interact with the lift cylinder depending upon the position of the lockout mechanism to provide at least two stop positions allowing minimum mower heights in each stop position to be established. The lockout mechanism further includes a bias apparatus and a lockout limiter to enable a specific lockout height to be imposed with minimal impact other operational aspects of the wheel lift assembly.