Mount Sylvania

Mount Sylvania is an extinct shield volcano in Southwest Portland that rises prominently above the surrounding landscape. The summit features a weather station, radio antenna, and benches positioned to take advantage of views across the Tualatin Valley and the West Hills area.

The mountain formed over a million years ago as part of the Boring Lava Field, a volcanic system that also produced Highland Butte and Larch Mountain nearby. This volcanic field shaped the wider regional landscape during the geological past.

The name comes from Silvanus, the Roman deity of forests, while the summit area is called Nansen Summit Park in honor of Norwegian polar explorer and Nobel Peace Prize winner Fridtjof Nansen. Visitors can see how the peak serves as a local landmark that connects the city to the natural landscape around it.

The summit area is open during daylight hours but closed between 10:00 p.m. and 6:00 a.m., so plan your visit accordingly. The peak can be quite windy, so bring appropriate clothing when visiting during cooler months.

Portland Community College built its Sylvania campus on the western slopes of this peak, making it an unusual case of a major educational institution sharing the mountain with recreational visitors. This blending of academic and natural use distinguishes it from other volcanic summits in the region.

Location: Oregon

GPS coordinates: 45.43816,-122.72211

Latest update: December 12, 2025 14:40