hike for kids in Colorado

“I'm planning a trip for my family, including 2 kids ages 9 and 12 in Colorado in August. I'm looking for recommendations of high-quality spots for car camping or easy backpacks. I'm particularly interested in the San Juans area, including hiking/camping options at drop-off points from the Durango/Silverton narrow gauge railroad.

Any specific advice or tips to info sources would be greatly appreciated.

Thanks”

“fun fun fun!!!”