Walking parks and playgrounds, swinging their machinery to and fro. They're hobbyists, but also members of the community laboring over local schools and recreation areas.

They are the Rogue Valley Coin Shooters, a group of treasure hunters aided by metal detectors. While most members pocket plenty of coins long forgotten in blades of grass, they also pick up crushed jagged aluminum cans, nails and other sharp items.

"It is very much an opportunity to be of service," said Gary Petersen of Medford. "We find just a whole array of stuff, anything you can imagine people will lose. I found a 14-inch knife hidden in a bush at a school one time."

Petersen has been metal detecting for 20 years and frequents the parks in Ashland.

"I think a lot of people see us like grumpy old men walking around out in the park," he said. "They don't really understand or don't know much about metal detecting."

People can contact the group if they have lost something valuable they wish to have found.

"If you lose a ring in your yard while gardening, you can call the club or one of us individuals and we will come look for it," Petersen said.

"We have a 50 percent success rate when we get called out," said Ed Redfield of Medford.

Redfield has been metal detecting for 22 years and is the Web master of the Rogue Valley Coin Shooters Web site.

Redfield recalls a hunt where he was looking for a class ring that had been missing for 12 years. After three swings of the detector the ring was found. Another time he was called out, he searched a large field for more than 10 hours hunting a man's wedding ring that was never found.

"It is not a profitable hobby. On an hourly basis it does not pay off," said Ed Winslow, a financial advisor by trade and member of Rogue Valley Coin Shooters. "It's fun to have a club and share what you've found. All these old guys doing it, it's the little kid in them. You're just redefining the treasure."

Members of the Rogue Valley Coin Shooters adhere to a code of ethics which stresses asking permission to hunt on private property, leaving no trace, obeying treasure hunting laws and returning valuable property. Metal detecting is allowed in all Ashland city parks. Destruction of landscaping is not permitted and interference with other park users is not permitted, according to the group's Web site.

Petersen concedes that there are those involved in metal detecting that do not follow the ethical guidelines.

"People who are robbing archeological sites or using shovels and not filling holes in, we get upset about that. It gives us all a bad rap," he said.

As with any interest, metal detecting has its own jargon.

"Gary and I call ourselves 'Park Pirates,'" Redfield said.

Hunting or metal detecting is also referred to as "swinging the coil," according to Redfield.

The metal detectors can pick up all kinds of readings, such as "hot rocks" which are rocks with high mineral content that trigger the detectors.

"The areas that have hot rocks have millions of them like towards Lost Creek Lake," said Redfield. Hunters using metal detectors try to stay out of these areas as well as locations with low hanging power lines which disrupt the signals.

Hunting in an area with lots of disturbances or non-valuables like nails and metal trash can be frustrating. Redfield recalls a time he was hunting in a park on Walker Street.

"I was two swings from quitting when I found a lead plate. I cleaned it up and it was a lead printing plate from a newspaper," said Redfield. Once it was cleaned up he realized it was a plate for a picture. "It was a Victorian era woman with her hair in a bun with a really long cigarette holder. I researched it and found out it was a cigarette advertisement from the 1930s."

Members of the club are addicted to the thrill of the hunt, which comes in many forms. After an item is found, if it is of value, many will try to find the owner, or for a historical item, research is conducted to find out more about it.

"If we find a class ring, most of us try to return that stuff, which is kind of fun, because you have the item and then you have the hunt to find the person it belongs to, and that's pretty exciting," Petersen said.

Donating monetary finds to charity is common among club members. Petersen donates two thirds of his coin finds to a charity that provides aide in foreign countries.

More information about metal detecting can be found at roguevalleycoinshooters.com.