Texas never had a "territorial prison" because Texas was never a territory. Unlike nearly every other state, Texas was an independent sovereign republic, and became part of the United States of America after a treaty was negotiated between the two nations (i.e., the Republic of Texas and the United States of America).
Jason and Nash make comments about George's donkey. It is a mule that George is riding.
There is no saguaro cactus in, or anywhere near, Texas.