Description - As you travel east along this 101-mile byway, you will experience lush green forests, the marine beauty of Puget Sound, pastoral valleys, and a dramatic mountain landscape. You will also pass through a complete revolution in climate, geology, and hometown style.
Interstate 90 is the primary east/west highway in Washington. It begins at the historic Seattle waterfront and travels east over the Cascade Mountains to the dry plateaus of eastern Washington.
Each year, over 20 million vehicles travel this route, making I-90 a very popular gateway between Washington's largest city and its diverse and striking landscapes.
- The Mountains to Sound Greenway - I-90 is known for it's Historical, Natural, Recreational and Scenic Attractions.Mountains to Sound Greenway takes the traveler from Puget Sound to the forested mountains of Wenatchee and Snoqualmie National Forests. It crosses 3,022-foot Snoqualmie Pass, travels alongside beautiful mountain lakes, and provides access to abundant outdoor recreation possibilities. Although it follows the Interstate, several exits provide access to the national forests and opportunities for camping, picnicking, fishing, and hiking.
Recreation - There are three national forest campgrounds and one state park located a short distance off the byway. Tinkham, Denny Creek, and Crystal Springs are national forest campgrounds. They are generally open May through September and have an RV length limit of 22 feet. Hookups are not provided at any of the national forest campgrounds. Tinkham has 48 RV and tent sites; Denny Creek has 33; Crystal Springs has 25 sites. Lake Easton State Park is near the town of Easton. It has 45 campsites with complete hookups and 92 without. The park provides access to nearly 40 miles of trails for hiking, backpacking, and cross-country skiing in winter.
Alpine Lakes Wilderness Area lies north of the byway. Hikers and backpackers will find over 600 miles of trails running through the area, including the Pacific Crest National Scenic Trail. Byway travelers can exit I-90 at either Exit #80 or Exit #84 and travel north through Roslyn to the road's end. Numerous national forest campgrounds are located along this side trip.
Climate - Washington's climate varies with each region. The Cascades split the state and alter weather patterns. The terrain east of the mountains receives significantly less rainfall than that west of the mountains, 12 inches is the annual average. Temperatures in this region are lower during the winter months, because it is landlocked. Frequent winds coming down from the mountains also contribute to the low temperatures of eastern Washington. Western Washington is temperate, due to the coastal geography. The water is a stabilizing force for the climate, making extreme temperatures rare. The area receives large amounts of rainfall from Pacific storms and some snow during winter months. The mountains of Washington receive large amounts of water-laden snow from October through May. These peaks remain snow covered throughout the year.
Mountains to Sound Greenway is in west-central Washington. It follows I-90 between Eastgate, which is just east of Seattle, and Ellensburg. The byway is about 100 miles long and remains open year-round. Use of chains or snow tires are generally required in winter over Snoqualmie Pass.
Directions from : Interstate 90 is Washington's primary east/west highway, with well-marked entry signs beginning in downtown Seattle (eastbound) and in Spokane, Ellensburg, and Cle Elum (westbound).