Planing a trip soon to an area I’m not familiar with and was curious is anyone has found a map source that would show tall towers.  

Google earth?

I use this one for any flights that are in areas that I'm not familiar with and so far so good.
http://www.fccinfo.com/fccinfo_google_earth.php

https://play.google.com/store/apps/dev?id=7133415022327536166 , shows the map with cellphones towers

In the UK the "Drone Assist" app shows things such as electricity pylons, etc. It's available for Android and Iphone.

I for one will not fly near cell towers,  radio interference may cause problems with flying your drone,  it happened to me,  the drone was near the top of the mountain and stayed there for three days until a good friend of mine found it.

Aviation maps may show towers.  

Hi, Thanks for the inquiry. Hope you'll get the best recommendation in regards to your concern. I would recommend checking our geo zone map for you to be able to determine if the location is restricted or not. Please see the link below for your reference. Thank you.

www.dji.com/flysafe

If you really want to fly safe, the best map is  Aeronautical charts.
They contains every tower, antennas, tank, smokestack etc., you will need to watch out for.

A good one to use is Skyvector
Here are symbols to look for

I use http://www.antennasearch.com/
Its  very localized and will cover any tower down to just a few feet tall by the no name local wireless company.
I found out there was a wireless provider in my area now that I didn't know about. Good thing to know living this rural.