Developing visualization on zip code level data

Question

I'm trying to use the zip code data from the census (any year that works). I have 5-digit zip code data that I need to match up to a map/shape file. The problem is that the zip code tabulation files from the Censsus ZCTA that can be found here http://www.census.gov/cgi-bin/geo/shapefiles2010/layers.cgi have holes in them. I am assuming these are lakes, parks, and wilderness areas. However, every zip code map I've seen do not have these. Is there a resource or method of combining these to create a solid zip code area?

Also, are there any other alternatives to zip code tabulation areas? Google maps will not work for what I am doing unfortunately. :(

EDIT: I am aggregating zip codes based on the data I have. I was hoping that some of these regions would be absorbed by other zip codes so when they are aggregated (based on the data I have) it would show different regions without these holes.

Answer 1

Per the USPS, national forests and bodies of water do not have zip codes. Zip codes are defined by address assignments, not by polygons.

See http://www.census.gov/geo/reference/zctas.html