Answer: Here,
1. searched for the Fountain of Youth : Ponce de Leon
2. discovered the Mississippi River : De Soto
3. explored southwestern America for Spain : Coronado
4. established St. Augustine : Menendez
5. founded Santa Fe : Piralta
6. began missions in Arizona : Father Kino
7. founder of Spanish California: Father Serra
8. established San Diego: Gaspar de Portola
Explanation: