Some people enjoy spending a day outdoors at the beach, others by playing a round of golf; then there are those who spend their leisure time embarking on quests to find benchmarks, a hobby akin to geocaching.

Benchmarks, more commonly called survey markers, are 3-inch wide bronze discs pegged to the ground, dated and stamped: “U.S. Coast & Geodetic Survey.” They turn up in the most unlikely places, from deep in the woods to city streets to rocky peaks.

Hunting benchmarks, or “benchmarking” as it’s called, isn’t a new activity; it’s been around since the mid-1990s. The hobby gained new popularity with the arrival of handheld GPS devices.

Before these amazing devices were widely available, benchmark hunters had to rely on topographic maps, a compass and coordinates supplied by the government. Many benchmarks are in plain sight but finding others can be pretty challenging.

Easy to find are the ones located alongside Wiscasset’s historic Powder House, the little brick building that sits on a stone outcropping overlooking Churchill Street. There are three benchmarks there, all dated 1934. It’s quite unusual to find three benchmarks at one location. It’s a mystery why the government surveyors chose to do this.

Many of these survey markers were set close to a hundred years ago, during the years from 1930 to 1950. They were placed in hundreds of thousands of locations across the country by the teams from the National Geodetic Survey, a part of the National Oceanic and Atmospheric Administration (NOAA). As to their purpose, without getting too technical, benchmarks serve as sort of starting points for surveyors and mapmakers.

Typically, when benchmark hunters find one, they usually photograph it and post the picture online. They often include directions for others who might enjoy searching for it. There are a number of websites devoted to the hobby. Removing or in any way altering a benchmark is prohibited by law.

Benchmarking grew out of another outdoor activity called geocaching, a high-tech scavenger hunt relying on handheld GPS units and satellite positioning. Teams hide everyday objects or packages of items someplace, then list its geographic coordinates for others to seek out and find.

A number of websites exist listing geocache locations in Maine and elsewhere. The hidden caches could be almost anywhere from a park to deep in the wilderness.

To learn more about benchmarking and geocaching, the more technical name is “geolocating,” we turned to Dave Kepler of Woolwich.

Kepler is a familiar face at the L.L. Bean retail store in Freeport. He’s worked in the store’s camping department for many years and enjoys geocaching with his daughter. For the Keplers, the hobby has turned into a year-round activity. They’ve sought out over a hundred different geocache locations in Maine.

“Geocaching’s been around since the late 1980s but has become more popular since cell phones have gotten more sophisticated. People can get started by downloading a GPS app,” Kepler said.

They can also buy handheld GPS units sold at outdoor outfitters. “The handheld units are still better and can be used almost anywhere in the world,” Kepler said.

Kepler said he’d heard of benchmarking and was interested in trying it. Together we embarked on a search for one of the more elusive benchmarks located in Wiscasset. The one we were searching for is located on Cushman Mountain, a part of the Cushman Preserve now owned and maintained by the Chewonki Foundation. Readers of the Wiscasset Newspaper will recall we featured this hiking trail in a story in our April 23 edition “Hikers will enjoy Cushman Preserve.”

Locations and directions to benchmarks are available online, while approximate locations appear on topographical maps. Even with the proper coordinates, the one we were looking for proved pretty elusive. Kepler’s GPS got us within about two yards of its location.

After poking around a bit we finally discovered the distinctive bronze disk in a stone outcropping hidden beneath a carpet of rock moss. The disk was stamped “Cushman” and dated 1933. It marks the hill’s highest point.

Using his GPS, Kepler calculated the elevation here was 253 feet. Before the trees grew up here, this spot must have afforded a nice view of the surrounding area, including the Back River far below.

If you take to the woods in search of benchmarks, Kepler recommends you go prepared by wearing proper footwear, carrying a cell phone and/or a GPS, bottled water, and a trail or topographical map. Insect repellent to ward off ticks and black flies is a good idea too. Remember some benchmarks and geocaches may be on private property and shouldn’t be explored without prior permission of the property owner.

The surprising thing about benchmarks is they’re usually in plain sight and quite easy to find, unless, like the one on Cushman Mountain, they’ve been obscured by Mother Nature. Finding these historic surveying discs can be quite challenging, but rewarding if your search is successful!