Paul Claus' unusual twist on geocaching got its start in an unexpected way. As his daughter Logan tells the story, the Alaska pilot, guide and owner of Ultima Thule Lodge was hosting a friend from Switzerland several years ago, when that guest spotted a moose shed from the air and returned with a set of coordinates and a challenge: Could Claus locate the shed, too?

The flight that followed inspired Claus to develop an annual invitation-only event that combines a treasure hunt sensibility with two of the best aspects of the state's aviation environment: stunning scenery and off-airport operations.

The event is launched each spring from Claus' lodge in Wrangell-St. Elias National Park. It engages about a dozen invited competitors in two days of fun that mimics the popular activity of geocaching.

On the first day, participants place six marked hard-boiled eggs (biodegradable, in case they aren't retrieved) and recorded locations with GPS coordinates. On the second day, after sharing all the coordinates, they go looking for each site. Points are obtained by finding sites and having one's own eggs found (thus encouraging participants to make their sites accessible).

According to Claus, the few rules are basic and safety-oriented: All aircraft must be on big tires (no wheel/ski combinations are allowed), each team must include both a pilot and spotter and the sites must be located within a 25-mile radius of the lodge.

"My biggest concern is always safety," Claus wrote in a recent email, "and we have had only one bent prop in the last six years. I divide the 25 mile radius into 4 sectors (A,B,C,D), every team is assigned a sector and they must start in that sector each day; after that they can go where they like. There is [also] a pre-event meeting where the spotters/helpers are admonished to be vigilant in looking for other planes."

This year, while Logan flew with her father and his spotter, she mounted a GoPro Hero4 Silver camera on their Cessna 180 and took along a Canon 70 DSLR to shoot footage on the ground to make the video above.

"The Geo Cache is my favorite weekend of the year," she said. "My dad got me into both flying and photography and this year I just wanted bring it all together in making a video."

Logan, who works as office director for the Alaska Airmen's Association, won the event in 2014 with her brother after discovering 35 finds. But winning isn't really the point of the event; mostly it's about getting out and flying with good friends and family and enjoying Alaska in a new and creative way.