Mo. Rev. Stat. § 313.670: Minors — prohibited from betting — presence prohibited, exceptions.

1. No race track licensee shall knowingly permit any individual under the age of eighteen years unless accompanied by a parent or guardian over the age of eighteen to be admitted to any pari-mutuel wagering area during a race meeting, nor shall any race track licensee knowingly permit any person under the age of eighteen years to wager on any horse race conducted by the organization licensee.

2. No individual under the age of eighteen years shall knowingly make or attempt to make any wager on any horse race subject to the provisions of sections 262.260 to 262.270 and 313.500 to 313.710.

3. Any individual who violates this section shall upon conviction be guilty of a class A misdemeanor.