About north of the California border, the highway crosses Siskiyou Summit, the highest point on I-5, and then drops down into the Rogue Valley through Oregon's southern mountains and towns such as Ashland, Medford and Grants Pass. Turning north across three passes to the Umpqua Valley and through Roseburg, the mountains tend to turn into hills, and as it reaches Cottage Grove, the road enters the Willamette River Valley. At Eugene the highway intersects I-105, a short spur route into Downtown Eugene. Some city highways intersect on I-5 in the Eugene Metro. The Interstate then heads almost due north, skirting Albany and Corvallis, passing through Salem, and crossing through Woodburn. There were plans to build a spur, called I-305, into Salem. I-5 covers in Oregon.