HOLDEN – It takes six adults to reach around the trunk of a silver maple on the banks of the Androscoggin River in Leeds. The 36-foot-diameter tree is the largest in the state – but maybe not the oldest, as some species grow more slowly. A European linden was planted in Phippsburg in 1776, according to church records.

Big trees, old trees and grand survivors will be the topic of a program at 7:30 p.m. Friday, April 18, at Fields Pond Audubon Center in Holden. Jan Ames of Project Canopy will give a presentation on Maine’s biggest trees, and Zip Kellogg, renowned as a standup canoeist in Kenduskeag Stream races, will tell stories – “fun, interesting, and even sad” – about his search for big trees.

Project Canopy – a partnership of Pine Tree State Arboretum, a private nonprofit organization, and the Maine Forest Service of the Department of Conservation – maintains a register of the biggest trees in Maine.

The trees are nominated by individuals, who must submit measurements of the tree’s circumference, height and crown spread – the nomination form even tells how to do this.

“It can get competitive,” Jan Ames acknowledged. “Arborists take pride in having the most trees on the list.”

Kellogg said he got interested in big trees six or seven years ago when he saw the register and thought, “Wow, some of these trees should be pretty neat to visit.”

The register, however, does not give directions, but just lists the towns the trees are in and, as Kellogg pointed out, most towns are six miles square. He had to do detective work on correspondence from nominators and a lot of rambling in the woods. His persistence was rewarded, however.

“It’s great fun when you finally find the tree,” he said. “You think, ‘what a wonderful tree.'”

Since Maine has been heavily logged, many of the mammoth trees are not in the woods but in communities and parks. A giant white pine in Morrill is so close to the road it has snowplow scars, Kellogg said. The nation’s largest yellow birch is on Deer Isle.

No matter how big or old, most trees are not protected by municipal ordinance, and it is up to the landowner to decide what to do with them. But most share in the excitement over the grandness of trees.

As Kellogg said, “We live in a treed part of the world, and they kind of grow on us.”

Admission is $5 for Maine Audubon members, $6 for nonmembers. To obtain information, call 989-2591.