State Route 18 is undergoing improvements to help safely connect Maple Valley and the South Sound with Snoqualmie and the I-90 corridor. This project represents a once-in-a-generation opportunity to improve wildlife connectivity from the Cascades to the entire Issaquah Alps, enhance recreation infrastructure for all, and provide safe, efficient highway transportation for our region. Unfortunately, while the current plan proposed by WSDOT this month tries to address important safety concerns, it does not include these recreation considerations.

Tiger Summit Interchange:

Tiger Mountain State Forest is a 13,745-acre natural preserve that incorporates the West Tiger Mountain Natural Resources Conservation Area. One of DNR’s most popular forests, Tiger is known for its lush landscape, hiking, and mountain biking trails.

Tiger Summit is a central trailhead that currently sees significant traffic from hikers and mountain bikers. The absence of an interchange will negatively impact accessibility to this outdoor recreation resource. The current WSDOT SR-18 Plan, which we realize faces budget constraints, will build a divider across the highway, requiring anyone trying to access Tiger Summit to travel one direction only, adding additional travel time, GHG emissions and safety concerns. This is not an adequate long term solution for an area experiencing such tremendous growth in recreation. Planning for the interchange should be included at this phase of the design process.

Hiking

There are 21 moderate trails in Tiger Mountain State Forest ranging from 0.8 to 11.9 miles and from 134 to 2,995 feet above sea level. Tiger Summit Trailhead is home to many of the Issaquah Alps’ most iconic trails, including the 15 mile Tiger Mountain Trail (TMT) and trails accessing neighboring Taylor Mountain.

Custer’s Bridge, about mid way on the TMT

Taylor Mountain Regional Park is nearly 2000 acre with an extensive trail system used by equestrians, hikers, trail runners, mountain bikers, and snowshoeing.

Mountain Biking

With many miles of mountain biking trails spanning a wide variety of difficulty - including a bona fide double-diamond DH trail and killer views of Mount Rainier from the summit - Tiger Mountain is one of Seattle's most popular mountain biking destinations. Taylor Mountain is close to Tiger and many of the trails are open year round. There is an unfounded reputation that the area is mostly muddy and less than desirable trails. What you will find instead are fun narrow trails that are open to mountain bikes. Future safe access to both mountains hinges on the WSDOT’s ability to look at the consistent growth in use for this area and plan ahead for an interchange at Tiger Summit.

What You Can Do:

We need your help to make sure our representatives know about our concerns with the current plan for SR-18. Find your representative below and contact them to voice your support of wildlife passages, a summit interchange, and recreation access to be included in the design for SR-18. Find a sample letter on our website here.

Representatives:

Mark Allison— SR18Improvements@wsdot.wa.gov — WSDOT Lead Project Engineer

Rep. Bill Ramos — Bill.Ramos@leg.wa.gov — 5th District State Representative

Rep. Lisa Callan — lisa.callan@leg.wa.gov — 5th District State Representative

S. Mark Mullet — mark.mullet@leg.wa.gov — State Senate
Find your representatives: https://app.leg.wa.gov/districtfinder/

Why the IATC is Advocating for an Interchange at Tiger Summit on Behalf of Recreation

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