This picture is most likely taken from the YMCA camp which gave the best view of Mt St Helens across Spirt Lake.. The YMCA camp was the favorite place for taking pictures of the mountain. Of course one could take pictures across the lake of the mountain from the trail that went all the way around the lake. There was also a Boy Scout camp near the YMCA camp but it wasn't used very often and the "Y" camp was open most of the summer. Let me tell you that it was cold cold swimming in that lake. I also went to the "Y" camp when I was a boy. It lasted two weeks and did I ever get lonely for dad and mom and home...haha... They came to visit on the weekend in the middle of the time I was there. There were lots of beautiful lakes all around the Mt and even a few old mines... The only road up to the lake was on the other side of the lake as you look across the lake in the picture. In order to get to the camp on this the far side of the lake from where the roads came in one had to ride a boat or hike for miles...haha... The "Y" had a motor launch and an old whale boat to haul all of the kids across the lake in...
Here is a little history of the "Y" camp 
http://www.backyardgardener.com/loowit/his.html
By Jim Sr.