Slate Peak is the highest road of Washington

Slate Peak is a high mountain peak at an elevation of 2,271m (7,450ft) above sea level, located in the US state of Washington.

Slate Peak

Where is Slate Peak?

The peak is located on the boundary between Okanogan and Whatcom counties, in the northern part of Washington, 15 miles northwest of Mazama, not far from the Canadian border.

Can you drive to Slate Peak?

Located within the Pasayten Wilderness of the Okanogan-Wenatchee National Forest, the road to the summit is totally unpaved. It’s called Slate Peak Road (Forest Service Road 5400). Starting at Hart's Pass, the road is 4.18km (2.6 miles) long. The road ends past Slate Pass on a locked gate just below the summit. Walk the remaining 1/4 mile to the top and enjoy the stunning views. The road to Hart's Pass and on to Slate Peak is the highest maintained road in Washington State.

When was the road to Slate Peak built?

The summit hosts a fire lookout tower (the highest fire lookout in the state) built in 1924. During the Cold War, Slate Peak’s summit was leveled (reducing its height by 41 feet) for the construction of an Air Force radar station. The station was never built, but the road to the summit remains. All that remains is a large concrete slab. The road was constructed during the 1950s as part of a defense project for the "Cold War."

Is Slate Peak open?

Set high in the Okanogan Range of the North Cascades, the road to the top is open from about early July to early October only. It is not passable for trailers, and wider vehicles such as motorhomes are highly discouraged. The peak is snow-covered much of the year.

Is the road to Slate Peak steep?

The road to the summit is very steep, reaching a maximum gradient of 17% through some of the ramps. Starting at Hart's Pass, the ascent is 4.18km (2.6 miles) long. Over this distance, the elevation gain is 368 meters. The average gradient is 8.80%.

Is Slate Peak worth it?

Don’t forget your camera! This drive up the mountain is totally worth it. Once you get to the top of Slate Peak, the panoramic views are quite spectacular. There aren't many places in the state where you can see views like these without a long hike. From the lookout, you have a 360-degree amazing view of all the great peaks of the Cascades. Go on a clear day; you won't regret it. Signs around the top of Slate Peak show the skyline and the names of the major visible peaks.

Is the road to Slate Peak difficult?

It’s a white-knuckle driving experience as the road narrows at times, following a scree cliff. Much of it is a single lane with pullouts, so you won't be racing up it and passing cars along the way. But it's in good shape and can be traveled by any highway vehicle with reasonable clearance. There's a section that's one lane, without guardrails, and there is a few hundred-foot drop off the shoulder. It's straight down and pretty scary.
Pic: Patrick McManus