POULSBO — Motorists who drove past the east intersection of the Olhava development late Saturday morning saw something other than a busy Highway 3 — most witnessed the start of a project to make a previously forested area natural again.

In collaboration with Washington State Department of Transportation, local environmental group Kitsap Trees started the third segment of its Kitsap Treeways project.

Nearly two dozen volunteers planted 455 Douglas firs and Western hemlocks along State Route 3. While 155 firs were planted at the Finn Hill overpass and along both hillsides at the B Street entrance to Olhava, 300 Western hemlocks were planted along the highway between Silverdale and the Sherman Hill overpass. The latter effort replaced hemlocks that had died last year, said Kitsap Trees community forester Jim Trainer.

“I pulled the trees out and they were planted correctly but with the drought last summer, we lost a lot of trees,” he said.

The average mortality rate of newly planted trees is 20 percent, Trainer said, noting that 60 percent of the hemlocks planted last year along the road died. To help prevent that from happening again, volunteers put down mulch and a special biodegradable cloth around the base of the trunk to help retain moisture, Trainer said.

The last part of phase three will be to plant another 75 trees between Sherman Hill and Thompson Road later this spring.

The fourth and final phase will be to plant vine maples this fall along a 3-mile stretch, starting at Thompson Road, then finish out the treeway to the Hood Canal Bridge with Pacific Silver fir or Sitka spruce next spring, Trainer said.

When the group started the project in 2003, it took 16 hours to plant 50 trees, said Kitsap Trees board member Mike Shepherd. But they’ve got a little more experience now, as it only took three hours to plant the 150 firs at Finn Hill and Olhava Saturday.

“We’re getting better,” he said. “I hope we finish this by this time next year.”

However, WSDOT wants the group to continue across the bridge into Jefferson and Clallam counties along the Olympic loop and back down to Bremerton, Trainer added. The agency provided the mulch, stakes and mulching cloth, Hood Canal Nursery provided the trees and all the labor is volunteer and organized by Kitsap Trees.

One of the final steps in the project is to obtain grant money for signage, so there will be a sign every four or five miles that will let drivers know what segment of the treeway they are in, explained Trainer.

The tree corridor’s primary purpose is to serve as an educational tool for children and as place where schools will be able to take field trips and learn more about the native trees, Shepherd said.