- Zebulon Pike: American explorer who led several expeditions into the American West, including the Pike Expedition of 1806-1807.
- Zachary Taylor: American military leader and statesman who served as the 12th President of the United States from 1849 to 1850. He was a prominent figure in the Mexican-American War and played a key role in the expansion of the United States into the Southwest.
- Zinc: A mineral that was discovered in the Western United States during the 19th century and became an important resource for mining and industrial development in the region.