I still carry a paper map but its been years since Ive used one. My problem is big cities, I just don't do well with all the signs, ramps and exits and a paper map would be pretty much useless. A few years ago I got a GOOD Garmin. Not the $79 one but up around $250. It has been totally pure awesomeness and has saved the day over and over again,, and way better than my smart phone. And use google to sit at my desk planning long trips, lots of good tools.

When I was truck driving there was a large Texas atlas available for about $20 but I don't know if it is still available.
I use Google maps now. But I have not been anywhere I need a map in the last three years. Grand son uses a GPS and swears by it.

This one ought to more than suit your needs.


Texas Road Atlas

One Map Place in Carrollton will have what you are looking for--best map selection I've ever seen for Texas roads and Texas lakes.

Get the updated Roads of Texas

have you noticed whether or not the Garmin is good with the unpaved county roads? Some years back I had a real estate agent get lost trying to find a house on an unpaved CR. She was using a GPS that was built in to a Lexus. I can see where the feedback on well travelled (paved) roads would get errors corrected quickly but where it might take years before an error is reported on a lightly used unpaved road.

I think you'd be better off buying a quality gps. You must have some internet connection available to post on her, and you will only need to connect it to the internet maybe once a year to update it. Otherwise, it doesn't need internet. It will always be up to date that way. I can assure you,they spend a lot more time and resources updating gps files than they do paper atlases. Then you also get turn by turn navigation.

It will be just as good as a paper atlas. They likely use the same surveys when making their maps.

Get a Garmin. Plug in any address and it will give you voice instructions while driving.