Probably best to see what the locals recommend. Check it out here!
Seated in beautiful, Rocky Mountain National Park. See Timed Entry Passes Link.
Endless trailheads and cool spots in Rocky Mountain National Park. Make sure you see the Timed Pass link for more information.
Most areas of Rocky Mountain National Park require timed entry passes. See this link for more information. According to their website you can book passes for September, on August 1.
Not up for a hike one day, try a 4x4 tour!