In order to round out your general Old West knowledge, you need to know about the camels of the Wild West. Yes, camels.
Camels have been used as cargo animals with great success in the deserts of Africa and Middle East for...well, as long as people have been there. You probably knew about that bit.
But did you know that in 1855, decades before the transcontinental railroad was around, General Jefferson Davis proposed to Congress that camels were key to westward expansion and would be useful for hauling army supplies? True story.
In 1857, the U.S. Army brought back 75 camels purchased from around the Mediterranean and the Middle East and stationed them at Camp Verde, located in central Texas.
The camels, badasses in their own right, lived up to their rough and ready reputation, traversing deserts and high mountains in the middle of summer during the driest seasons; however, there were some issues. Stubborn and not responsive to methods of training employed at that time (I personally relate), camels were simply too hard to handle.
So over time, camel popularity petered out, but indeed there were some camels in the wildest West!