EVANSVILLE, Ind. – Indiana’s Big Tree Register has been around for 50 years, and for the first time, a tour highlighting several of the state’s large trees will be offered by the Indiana Division of Forestry’s Community & Urban Forestry department.

The Big Tree Tour will be 9 a.m.-2 p.m. Aug. 3 in Evansville. The tour includes a bus ride around Vanderburgh County to see state and county champion trees, plus a walk through the nation’s largest urban old-growth forest, Wesselman Woods.

The state’s Big Tree Register, first published in 1974, was based off the American Forestry Association’s Big Tree Register that began in 1945, said Jacob Roos, urban forestry director for the Division of Forestry.

“Part of the reason we decided to do a Big Tree Tour is to bring the Big Tree Register to life,” he told Farm World. “You can look at the pictures of the trees on our website but until you see the trees in person, it is difficult to fathom how large they truly are. It is also important to highlight big trees in our communities and urban areas because the larger the tree, (the) larger the benefits they provide.”

Indiana’s register is unique in that it only includes species native to the state, he said. The register lists champion trees for every species. It was previously updated every five years, but has been updated continuously since last year. There are currently 90 trees on the register.

The largest tree currently on the register is a silver maple in Lawrence County. The tree has a circumference of 361 inches, a height of 103 feet, and crown spread of 106 feet. Close behind is a sycamore in Johnson County, which has a circumference of 320 inches, a height of 115 feet and a crown spread of 169 feet.

The total size of a tree is calculated with a formula of circumference plus height plus a quarter average crown spread, according to the Indiana Department of Natural Resources website. The individual tree of each Indiana native species with the highest total points is the state’s champion, the site said.

To measure a tree for the register, measurements of the trunk circumference, vertical height and average crown spread are required, Roos said. Instructions on how to measure may be found at on.in.gov/big-tree.

“I am not sure what the largest tree ever recorded on our register was,” he noted. “That would be a fun project. I do know there was a sycamore tree in Worthington, Ind., that fell in 1925 that had a trunk circumference of 507 inches. There is still a part of the tree that is on display in a park in Worthington.”

If the initial Big Tree Tour goes well, Roos said the agency plans to offer one yearly. The first tour is in Vanderburgh County because the county, and Evansville specifically, have the highest concentration of state tree champions, he said. Roos said he expects tours to be expanded to other parts of the state in the future.

The register only lists the largest trees at the state level, he pointed out. Some counties and communities compile their own local big tree lists, Roos added.

“We hope that after these tours, the public will start to look at trees in their community and neighborhoods with a different perspective,” he said. “We hope that people will start to realize that there are more giant, old trees in the community than they probably realize.”

The tour is limited to 20 people. Attendees are asked to bring their own lunch and drinks as lunch will be eaten before the tour of Wesselman Woods. For more information, contact 317-234-6741 or email urbanforestry@dnr.in.gov.