POTOSI, Missouri. Travis and Cindy were on a mission.

After parking their minivan in front of Mark Twain National Forest's Potosi Ranger Station, they turned on their GPS unit and stepped out of their vehicle.

They weren't there to purchase a map, or to inquire about camping, or to buy a firewood permit. They were searching for something…something that they knew was very close by. And if they found it, it would be momentous because never yet had they been the "First To Find."

Time was of the essence, and even the damp and chilly air of that October 2011 morning was not enough to deter them. They had to find it, and find it first.

They walked down the sidewalk, past the Pollinator Garden, across the parking lot, and headed into the woods. As they approached a small vernal pool, they suddenly stopped. Did they see something? Maybe a bird flushing from a bush? Or a frog jumping into the pool? No, they saw something much less obvious.

Travis walked a few steps further, stopped again, turned around, then kicked some leaves and exclaimed "I found it!" Pulling an old ammo box out from behind a tree, they both grinned from ear to ear. This was what they were looking for. This was the geocache!

Travis and Cindy represent hundreds of people who participate in geocaching, or treasure hunting on Mark Twain National Forest.

This particular geocache was put there by Mark Twain National Forest Employee Marge VanPraag.

A geocacher herself, Marge has enjoyed encouraging others to participate in this recreational pastime.

"I have been a geocacher for almost 2 years. I guess you could say I'm hooked," Marge says. "Kids especially have fun with it. I geocache with my granddaughter and she loves it."

Geocachers are required to contact the Forest Service before placing any geocaches on Mark Twain National Forest. It is estimated that around 100 geocaches are hidden on Mark Twain National Forest, including one at almost every Ranger Station.

Geocaching extends all the way from the local Ranger Stations to USDA Forest Service's National Headquarters in Washington D.C., which has been a virtual geocache since August 12, 2001.

Once established, the geocache is announced on the website Geocaching.com, which is how Travis and Cindy learned about the geocache at Mark Twain National Forest's Potosi Ranger Station. Upon returning home, they will record their finding of the geocache on the website.

"We love being outside and exploring. This is something we can do together, and it gives us an excuse to go places we would normally never visit".

After recording their names in the small notebook and pocketing a Mark Twain National Forest turkey pin as their "First to Find" prize, Travis and Cindy place the geocache back where they found it and lightly cover it with pine needles.

As they walk back towards their car, hand-in-hand, they stop for a moment to read the interpretive panel in Mark Twain National Forest’s Potosi Ranger Station's Pollinator Garden. They didn't come to look at the garden, but as long as they were there, why not?