Owning the property long-term is one of the best strategies for these tax properties because it takes the resale & title insurance issues off the table.
I always have the best luck calling ahead and asking questions to the county here is my list for your situation:
1) Can I purchase at your tax sale while living in Texas or do I need to be there in person?
2) What are your payment options (cashiers check, cash, personal check, credit card)?
You should now download and install Google Earth on your computer and look at the selection of older photos for the land you want to buy. Screenshot and make a gallery of photos so you can quickly scroll and pinpoint potential issues. Mineral rights on property in Colorado require a high amount of research. Contacting the county assessor and asking if someone else is paying for mineral rights on the land is a good start.
Finally, always assume someone else wants that tax property you are looking at. Have another one that you would want to bid on in-case the first gets taken.
Good luck, hope you share your results with us, we enjoy the experience!