Durango, already home to the state’s largest known specimen of three tree species, has learned it harbors the biggest black locust in Colorado.

Neal Bamesberger with the Colorado Tree Coalition said Wednesday that a black locust at 721 East Third Ave. is the new champion of its species, dethroning a black locust in Boulder.

The biggest trees are determined by a formula using height, circumference and one-fourth of the crown spread, Bamesberger said.

The formula gives Durango’s black locust 262.55 points, compared with 243.73 points for Boulder’s ex-champion.

The black locust is native to the United States – from northern Georgia and Pennsylvania to Arkansas and Oklahoma. It’s known for its pendulous strings of nose-tingling, fragrant white blooms.

The wood – tough, hard and heavy – when milled is used to make furniture or flooring.

The new champion black locust dominates the rear patio of the home of Fredette Eagle. It’s 76 feet tall, 55.2 inches in diameter and has a 53-foot crown spread.

Durango already has the largest known juniper, Utah juniper and Rio Grande cottonwood in the state, according to Colorado Tree Coalition records, which are updated every year. The city also has several other species of trees of lower rank.

“I measured our champion cottonwood on Silverton Avenue,” Lindsay Gartner, assistant district forester with the Colorado State Forest Service in Durango, said Friday during a visit with Dave Dilling, a forester with the agency, to measure the black locust.

Gartner said state foresters sometimes nominate trees for championship consideration if they come across an impressive specimen in their routine activities.

Eagle, who is vacationing in Florida, is familiar with champion trees. She said Wednesday by telephone that a chestnut oak and a Canadian hemlock on the property where she sometimes lives in McLean, Va., are Fairfax County tree champions.

“I put in a sprinkler system for the black locust,” said Eagle, who first came to Durango in 1996 on a visit with ragtime pianist Johnny Maddox. “The tree has blooms every year, but every other year they’re spectacular.”

The Colorado Tree Coalition is a nonprofit founded in 1991 with a mission to lead state efforts to preserve, renew and enhance community forests. Funding for the organization, which has an all-volunteer staff, comes from grants, donors and partners. The latter group includes the Colorado State Forest Service, the U.S. Department of Agriculture, the Rocky Mountain chapter of the International Society of Arboriculture and Xcel Energy.

Ron Stoner, arborist for the city of Durango, said the non-native black locust was brought to the area by pioneer families. Black locusts grace two city parks – Fassbinder and Viles.

“It’s a majestic tree and looks good in contrast to maples and elms,” Stoner said. “It’s a nice variety in an urban forest.”

Stoner called the recognition given Eagle’s black locust another “medal on the chest of Durango,” which has been a Tree City USA designee for 32 years.

The Tree City USA program is sponsored by the National Arbor Day Association. Cities so designated must commit to certain standards, among them spending $2 per capita annually on tree care and having a board to oversee forest issues, Stoner said.

Bamesberger receives 25 to 30 biggest-tree submissions a year. He verifies some claims but also relies on others such as state foresters or city arborists to authenticate claims.

daler@durangoherald.com