From the Columbia River to the Siskiyou Mountains, Highway 99 traverses 300 miles of western Oregon. Big cities and small towns, the level Willamette Valley and steep hills, rich agricultural lands and tall evergreen forests, and rushing rivers all lie along its path. Arising from an early network of emigrant trails, stagecoach routes, and farm-to-market roads, the highway had developed into Oregon's major transportation corridor by the end of the 19th century. The dawn of the automobile age saw an exponential increase in traffic, creating a greater demand for improved roads; these better roads, in turn, created yet more traffic for both business and recreation. Roadside businesses, such as auto courts, restaurants, and service stations, sprang up along the highway to cater to a new type of motorist-the tourist. Today, much of Highway 99 and its predecessor, the Pacific Highway, remain in daily use.