What if I own 29/30th of a piece of property, and the other 1/30th owner cannot be located. Is there anything else you can do to try to notify the other person via a newspaper ad or something and then hold the money in escrow in case the other person is ever found?

In some states there is a procedure called "quieting title" that may help; you need an attorney.

Normally without that other person you can not sell the property without them signing. You will have to try some court action to clear the title into your name only to be able to sell it, The exact way to do this in your state may vary greatly, you will need a real estate attorney for this.