Is the name Yellow Pages protected by trademark or copyright in the USA Can I legally name my directory the yellow pages?

There are several hundred different companies using the phrase "yellow pages" or "yellow page" as part of their trademarks, but (at least in the USA) they cannot prevent each other from using the words "yellow pages" in other combinations (e.g., "Bumpkinville Yellow Pages" could be a new trademark). To even be considered for a federal registration of a trademark including "yellow pages", you would be required to "disclaim" any proprietary right to those words, apart from your specific combination (i.e., with other words, with a distinctive logo, etc). A descriptive and non-distinctive brand is not a very valuable marketing tool, and it only takes a bit of imagination to come up with something much more catchy.