The Willamette Valley
 

McIver Park, near Estacada (Northern Willamette Valley)

The Willamette Valley is the most populated region in Oregon. Its fertile, level ground and moderate climate have allowed European and Asian people to settle there since the mid-1800s. Today, the valley boasts a total population of approximately 1.5 million people and is some of the richest farmland in the country.
 
Location
The Willamette Valley is located in the western section of Oregon, running north to south between the Coast Range to the west and the Cascades to the east. Its northern end terminates at the Columbia River while its southern boundary abuts a meeting of the Cascades and Coast Range Mountains (see map below).
 
History
Most people think the Willamette River, which runs the entire length from Eugene to Portland, formed the valley. In reality, this valley (actually a plain) was formed by doing nothing at all. The area was originally seafloor. As the subduction zone at the western edge of the North America plate shifted, new volcanoes formed the Cascades mountain range. The Coast Range also merged with the North America continent from the Pacific Ocean. The sea drained away to the north and a wide plain remained. Roughly, 15000 years ago, as the most recent ice age came to an end, an ice dam in Montana broke and created the Missoula Flood. An enormous mountain of water scoured eastern Washington and poured into the Columbia River. Debris blocked the flood and it was diverted into the Willamette Valley. This happened approximately 40 times over a 2000-year period. As a result, the valley has a rich, deep layer of sediment that has proven to be an agricultural paradise.
 
Climate
The valley has a moderate climate. The effects of its proximity to the Pacific Ocean give the area wet but mild winters. Summers are dry and can have hot days, but uncomfortable weather does not linger. The Columbia River Gorge opens into the Willamette Valley on the north end, which allows occasional cold and hot spells from the higher deserts to the east. The valley lies in the rain shadow of the Coast Range on the west side and touches the Cascade foothills on the east side. The overall effect is an average rainfall of 40 to 50 inches, average winter highs in the 50s and summer highs in the 80s.
 
Ecosystem
The Willamette Valley ecosystem is no longer wild, having been extensively altered and controlled by human activity since the 1840s (even further back including Native Americans). Presettlement Vegetation ca. 1851 (S. Gregory, et al., http://www.fsl.orst.edu/pnwerc/wrb/Atlas_web_compressed/4.Biotic_Systems/4b.presetveg_web.pdf) describes it best:
 
“When the first Euro American settlers arrived in the Willamette Valley, they found the valley clothed in tall grasses, so tall that cattle were hidden from view. The appearance was that of a “park” with wide swaths of grass punctuated by groves of spreading oak trees (Oregon white oak, and in Lane County some California black oak). Dense gallery forests lined the Willamette and its tributaries with associations of Douglas-fir, Oregon ash, black cottonwood, alder, big leaf maple, western red cedar, and willows. Dense patches of Douglas-fir forest and oak forest were locally found in ravines, on hilltops, and on the floodplain.”
 
Today, the valley contains farms, town, and cities. The region’s major export is some variety of farmed commodities, such as hay or fruit trees. Linn County in the center of the valley greets visitors driving the I-5 with a sign that proudly states “Grass Seed Capital of the World”. Wild animals have been reduced to deer, raccoons, squirrels, etc. The larger animals were forced to retreat into the mountains and hills long ago.
 
Human Activity
As stated above, human activity is extensive in the Willamette Valley. Agriculture is the largest exploit and the area is home to large cities, including the Portland metropolitan region and the state Capitol of Salem. This section of Oregon is the most densely populated and, as a result, all political decisions for the state are made here.
 
Things to See
There are literally thousands of things to see and do in the Willamette Valley. Since this is not a book, I will exclude city listings. For activities in the populated areas, I direct you to this site: http://www.oregonbeat.com/calendar/index.php?calendar=8. Alternatively, you can look up each city’s Chamber of Commerce for more ideas.
 
-  Covered Bridges: Roughly, 50 bridges remain throughout the valley. Most are still drivable. http://www.oregon.winecountry.com/about/travel/itinerary/2006/02/willametteValleyCoveredBridges.html
 
-  Enchanted Forest: A theme park near Salem. http://www.enchantedforest.com/enchanted_forest.html
 
-  Oregon Garden: 80 acres of tended gardens open to the public. http://www.oregongarden.org/
 
-  Silver Falls State Park: 8000 acres of park with ten waterfalls, camping and hiking trails. http://www.oregonstateparks.org/park_211.php
 
If You Go: Be prepared to get wet from October to June. July to September is generally comfortable, but there are occasional heat waves where temperatures can reach 100+ degrees. The I-5 freeway is the main artery of transportation in the valley, making the region easy to explore. There is morning and evening rush hour from Salem to Portland, so be sure to take that into account when planning your excursions.

Original text © 2009 S. Skiles