In 1879, the USGS began to map the Nation's topography. This mapping was done at different levels of detail in order to support various land use and other purposes. The 2016 versions for the state of Texas and all other states are available here.
These 2016 topo maps are based on a 7.5 series and scaled at 1:24,000 in an area called a quadrangle. Enter your requested quadrangle at checkout or If you are not sure which quadrangle you are interested in purchasing you can look them up here: https://www.usgs.gov/core-science-systems/ngp/tnm-delivery/
by double clicking the area on the map you are interested in or feel free to call us anytime at 830-438-4080 and we will be happy to help you locate the specific quadrangle(s) you need.