An earlier discussion had a comment in it that stated "And I would wager all the money in my pocket that you cannot find a single current state law which defines rape (or the equivalent offense, usually sexual assault) as purely penetrative"

Idaho:

18-6101. Rape defined. Rape is defined as the penetration, however slight, of the oral, anal or vaginal opening with the perpetrator’s penis accomplished with a female under any one (1) of the following circumstances.

Another thing many people do not consider is the impact of the FBI UCR definition. Over 40 states report to the UCR and even though the definition of "Rape" in that State may not be gender biased it can be skewed when they report it to the UCR.

Starting on page 19 of the FBI UCR handbook they state this:

(Forcible Rape Defined) "The carnal knowledge of a female forcibly and against her will"

Carnal knowledge is defined by Black’s Law Dictionary, 6th ed. as “the act of a man having sexual bodily connections with a woman; sexual intercourse.” There is carnal knowledge if there is the slightest penetration of the sexual organ of the female (vagina) by the sexual organ of the male (penis).

Agencies must not classify statutory rape, incest, or other sex offenses, i.e. forcible sodomy, sexual assault with an object, forcible fondling, etc. as Forcible Rape

By definition, sexual attacks on males are excluded from the rape category and must be classified as assaults or other sex offenses depending on the nature of the crime and the extent of injury.

So when those 40+ states report their stats to the UCR they have to follow those guidelines. For example Ohio:

Ohio’s Office of Criminal Justice Services has the following definition listed in their crime definitions:

FORCIBLE RAPE = The carnal knowledge of a female forcibly and against her will. Assaults or attempts to commit rape by force are included here; however, statutory rape (without force) and other sex offenses are not included.

This can skew the data quite a bit if you are not paying attention to the language.

Idaho also states this:

18-6108. Male rape. Male rape is defined as the penetration, however slight, of the oral or anal opening of another male, with the perpetrator’s penis, for the purpose of sexual arousal, gratification or abuse, under any of the following circumstances: