An inheritance is not considered income and thus not exposed to tax law.
The beneficiary of the bequest is the sole owner.
Separate property. Generally, separate property is:
Property that you or your spouse owned separately before your marriage.
Money earned while domiciled in a noncommunity property state.
Property that you or your spouse received separately as a gift or inheritance during your marriage.
For more info on this subject see:
Publication 555 (5/2007), Community Property