Rocky Mountain National Park superintendent Darla Sidles will retire June 30 after seven years leading the country’s fourth-busiest national park, leaving behind an office at the Beaver Meadows Visitor Center with a stunning panoramic view of Longs Peak and its sheer east face. She took over the top position at the park after serving seven years as superintendent at Saguaro National Park in Arizona. “It’s been such a passion and honor to work here,” Sidles said Thursday in an hour-long interview.