Fort Collins, Colo., photographer Jeff Olson ventured out to Rocky Mountain National Park, located outside of Estes Park., Colo., on the first day of fall to check out the sights. Established in 1915, the park is family vacation destination that offers many outdoor experiences, including easy nature hikes around crystal-clear mountain lakes to daring rock scrambles up waterfalls and mountains. The park has elevations ranging from 8,000 feet in the wet, grassy valleys to 14,259 feet at the weather-ravaged top of Longs Peak. Sights for autumn visitors include the spectacular color of golden aspens and bull elk and their herds of females and calves.