What do the white spots on this map of the MLB TV blackout zones signify?

Here’s the map:

http://us.i1.yimg.com/us.yimg.com/p/sp/tools/med/2006/06/ipt/1150742098.jpg

This shows what each MLB team calls their territory when it comes to TV blackouts in the MLB.tv service. But what are the white spots all over?
They’re not lakes because there’s not one in Utah, they’re not place where there is no internet/cable because of the huge areas near Washington, D.C., Las Vegas, and southern Florida, I don’t think they’re indian reservations, they aren’t problems with the scanning of the map because there are city names over some of the spots..What the heck are they?
Batman thanks for reading the question.