The higher the cloud layer, the longer the sunset lasts for the simple reason that the higher the clouds are, the longer the receding sun illuminates the bottom of them. I shot this picture perhaps 45 minutes after sunset. The whole spectacle lasted about an hour.
The Tualatin River begins in the Coast Range west of Portland, Oregon and meanders through a partly rural, increasingly urban valley until it joins the Willamette River near West Linn, a few miles upstream from Portland.
This picture was taken from the Shamberg Bridge on Roy Rogers Road, just north of Sherwood, Oregon in the Tualatin National Wildlife Refuge. Since the time when I took this photo, this road has been straightened and converted to a high use, high speed arterial. In the interest of safety, I recommend not using it for a photo platform today.
The only filtration used on this photo was a graduated neutral density filter. The shot was made on Fuji Velvia film, which tends to saturate reds. No further enhancement was done.
Ash Creek Images
Photographs of the West by Doug Gorsline
High Clouds Produce an Intense Sunset Over the Tualatin River Near Sherwood.