As Doug suggests, there was a servicable HIDTA map, but they appear to have reorganized the ONDCP web site and I cannot find it either.
You can use the Census Bureau
to identify the county where the zip code is located. Then you can go to a U.S. map
where you can click on the state and it will take to you information that lists the HIDTA counties in that state. (The previous ONDCP map was far more functional.)
With FinCEN's IT modernization program use of a zip code on a BSA form will automatically identify the county and any HIFCA or HIDTA status.
While neither of these observations actually meet your needs, that latter suggests that someone has built or is building a data base where zip code queries will identify HIDTA or HIFCA counties. We will hope they make it accessible to the public.