A Silver Alert has been issued for a missing Flagstaff man, who was last seen at Cliff Castle Casino. Flagstaff Police say Donald Marvin Stonebreaker was at his home Monday afternoon at around 12:30 p.m. His caretaker left for about an hour and came back to find him missing. The caretaker also noticed he took his light turquoise 2003 Toyota Prius with Arizona plate CTA6269. Stonebreaker was seen at Cliff Castle Casino Monday, but could be headed to Boulder, Colorado where he is originally from, or Sedona where he has property. Donald also suffers from dementia and has other immediate medical needs. If anyone sees him, or knows his whereabouts, contact Flagstaff Police at (928) 774-1414.