Best thing to do is contact your city/town parks and rec dept and ask them. Some cities in TX require permits and will allow MDing in city parks and whatnot. Others, don't, it's kind of hit or miss in TX.
When I visit my parents in Granbury, TX... I detect the city man made beach, and schools and parks no problem. But I also have in writing from the parks and rec that it is okay unless anyone stops me.
I know that the city of Austin prohibits the use of metal detectors, which sux. I know that you can detect at Canyon Lake. Corps of Engineer lakes are cool to detect at. Yeah, sux that Texas state parks are off limits. I see that you're a ways from the coast, but most of it is cool to detect at(except for the National Seashore and state parks, of course). Now, since most of the land in Texas is privately owned, there is a vast amount of land to detect if you politely ask the land owner if you can simply do some hobby detecting without damaging the property. You'd be surprised how many people are cool with it. If they say no, what have you got to loose? Just move on to the next property. DO YOUR RESEARCHSee where people use to congregate, etc. Best of luck to ya'. Let us know how it goes. Happy Hunting!
It all depends on what you want to find...If you want clad/current coins and poss. jewelry try school football/sports areas, parks, anyplace that people congregate .For old coins and jewelry try older homes,schools and churches and research old maps for buildings and parks that are no longer there, even ghost towns. I hunt alot of old parks,schools and churches...Good Luck....Tom