After the snow melted in the spring, I started going up to a viewpoint of the mountain in a clear cut just north of Goat Mountain on the west side of the mountain. There were no road blocks and no signs. But I was just a few miles west of the mountain.
On May 17, I decided to drive further north and found a viewpoint just above the South Fork Toutle River -- a scant 2.5 to 3 miles west of the mountain. I snapped a few photos, stuck around for a while to enjoy the view and left.
On May 18, I had promised someone I would go to the coast and we spent a nice sunny warm day over around Tillamook. We left Portland about 8:30 in the morning and had a wonderful day. Since I hadn't turned the radio on in the morning I was ignorant of the eruption going on until we returned to Portland about 4:30 that afternoon. Heading east on Highway 26 around Hillsboro I turned the radio on, and they said and "Now we go back to the latest on the Mount St Helens eruption." I looked over the hills and saw the towering eruption column for the first time and exclaimed "Holy Sh!!".
I've spent a lot of time since then photographing the mountain and area around it. Many comparison photos can be found on flickr at: http://www.flickr.com/photos/ujelang/sets/72157622174345423/ including the stunning comparison of the view from Norway Pass from 1985 to 2009: http://www.flickr.com/photos/ujelang/3516564157/in/set-72157622174345423/ In that set are also a few views taken above the South Fork Toutle River.
I've also published a book on blurb.com: http://www.blurb.com/bookstore/detail/1226387 which I think does an excellent job of capturing the feel of the landscape and the continuing evolution of the landscape around the mountain.