FLAGSTAFF, Ariz. (AP) — The first female superintendent of Grand Canyon National Park resigned Thursday, less than three years after she took the helm of one of the country's most popular tourist destinations.

Christine Lehnertz's resignation comes months after she was reassigned amid a federal investigation that cleared her of allegations of creating a hostile work environment and wasting park resources.

In an email to Grand Canyon employees, Lehnertz said the past few months have been life-changing and she reassessed her priorities.

"My experiences have served to reinforce the core of my lif...