Which river holds the title of the longest river in Texas?

The Rio Grande holds the title of the longest river in Texas. Spanning approximately 1,896 miles, it originates in the San Juan Mountains of Colorado and flows all the way to the Gulf of Mexico, forming a natural border between Texas and Mexico for a significant part of its length. The river's extensive course and significant cultural and historical importance make it an integral feature of the geography of Texas.

The other rivers listed, while important in their own right, do not match the length of the Rio Grande. The Colorado River, the Trinity River, and the Red River are all shorter, with the Colorado River being a major water source for Central Texas and the others serving critical ecological and economic roles in their respective regions. However, none of these rivers can claim the overall length that the Rio Grande does, which is a key reason for its status as the longest river in Texas.