Mount Si

Mount Si is a mountain summit in King County that rises to 4,167 feet (1,270 meters) above sea level. The main trail winds through dense forest and rocky terrain, reaching the peak after several hours of steady climbing.

The mountain was named after Josiah Merritt, a local settler called Uncle Si, who made his home in the Snoqualmie Valley during the 1800s. This naming reflects how European newcomers left their mark on the landscape.

The Snoqualmie people connect this mountain to stories about sɬukʷalb, an important figure in their traditional beliefs. The peak holds a special place in how they understand the land around them.

The climb demands sturdy hiking boots, plenty of water, and generally takes four to six hours round trip. Plan to carry enough supplies and start early, as the trail is steady and offers few places to rest or resupply along the way.

The summit area features the Haystack, a rocky formation that demands basic rock climbing skills to reach the absolute top. This added challenge divides casual hikers from those seeking a more technical experience.

Location: King County

GPS coordinates: 47.50696,-121.73911

Latest update: December 7, 2025 10:05