Just outside Seattle lies one of the largest conserved wildland areas near any major U.S. metro, thanks to decades of advocacy by the Issaquah Alps Trails Club. Seattle’s forests have transformed dramatically over the past two centuries – from towering conifer giants to fast-growing hardwoods after heavy logging.

On Cougar Mountain you can still find places where conifers dominate and the forest feels closer to its original character. Join IATC’s Svet Semov for a hike on the De Leo Wall trail, home to some of the highest density of conifers on Cougar Mountain. As we hike at a moderate pace, we will make stops to identify local trees and plants such as Douglas fir, Western redcedar, Bigleaf maple, Oregon grape, and salal. Along the way, we will discuss the impacts of climate change on local ecosystems, explore the history of De Leo Wall, and highlight recent IATC efforts in conservation and education.

Trailhead: De Leo Wall
Trails: De Leo Wall to Indian Trail
Distance: 2.4 miles
Duration: 1.5 hours
Elevation Gain: ~600 ft.
Parking: 8524 146th Pl SE, Newcastle, WA 98059 (there is street parking along this residential community)

Seattle Wilderness: Then and Now 8/16/26

Hikes with a Purpose