White Pass

White Pass carries US-12 over the Cascade Range in Washington, southeast of Mount Rainier and just north of the Goat Rocks. Within the state system the highway is signed SR-12. The summit sits at 4,500 ft (1,372 m). The pass is the cross-Cascades shortcut between Packwood on the west side, in Lewis County, and the Naches and Yakima area on the east side, in Yakima County.

Truckers care about this one for a simple reason. White Pass is the only year-round Cascade crossing between I-90 over Snoqualmie Pass to the north and SR-14 through the Columbia River Gorge to the south. It carries regular log-truck and commercial traffic, and the White Pass Ski Area at the summit adds weekend volume in winter. Unlike the North Cascades Highway, Chinook Pass, and Cayuse Pass, which WSDOT closes for the season, White Pass stays open all year.

A note on the climb. No WSDOT source gives a clean maximum grade percent or an exact climb length for White Pass, so any specific number you see online is unverified. What is sourced is the road segment itself: the full pass road from Silver Beach to Packwood runs about 28 miles and is paved but steep in parts (dangerousroads.org, a travel source, not a DOT). The chain-control corridor runs from Packwood to Naches, roughly 52 miles.

• Summit elevation is 4,500 ft / 1,372 m (WSDOT; Wikipedia).
• Highway is US-12, signed SR-12 in Washington, crossing the Cascades southeast of Mount Rainier.
• Connects Packwood (west, Lewis County) with Naches and Yakima (east, Yakima County).
• Only year-round Cascade crossing between I-90 / Snoqualmie Pass and SR-14 in the Columbia River Gorge (Wikipedia).
• Chain corridor runs Packwood (MP 135) to Naches (MP 187), about 52 miles (WAC 204-24-050; WSDOT).
• Chains must be carried by vehicles over 10,000 lbs GVWR from November 1 to April 1 (WSDOT; WAC 204-24-050).
• Not on WSDOT's seasonal-closure list; maintained year-round (WSDOT avalanche-control page).

There is no fixed seasonal or calendar closure for White Pass. It is maintained year-round and is not on WSDOT's seasonal-closure list, which covers Chinook Pass, Cayuse Pass, and the SR-20 North Cascades Highway. So there is no hard annual closing date to plan around.

For chains, the carry season runs November 1 to April 1. During that window, every vehicle over 10,000 lbs GVWR has to carry sufficient chains on the designated SR-12 corridor between Packwood (MP 135) and Naches (MP 187), regardless of conditions. When WSDOT posts "chains required," all vehicles over 10,000 lbs must actually chain up. The pass still closes temporarily and without much warning for storms, avalanche control, slides, and crashes, but those are short closures of hours to a few days, not scheduled events.

The cross-Cascades route over White Pass joined the state highway system in 1931 as State Road 5. The White Pass Highway itself was dedicated on August 12, 1951, finishing the year-round shortcut between southwest Washington and Yakima. Reporting on the dedication cites a project cost of roughly $6 million, about 3,500 people on hand, and around 1,000 cars crossing that opening day (Yakima Herald; Wikipedia, citing the Walla Walla Union-Bulletin). The road became U.S. Highway 12 in 1967.

The pass takes its name from Charles A. White, the surveying engineer who led the party that located it for the Northern Pacific Railroad in 1878. The White Pass Ski Area opened at the summit on January 11, 1953, and it is a big part of why the pass sees steady winter and weekend traffic. One darker dated event belongs to the air, not the road: on October 7, 2007, a single-engine Cessna Caravan carrying skydivers crashed near White Pass, killing all 10 aboard.