On our way out to Mount St Helens, one of the places we stopped was the Forest Learning Center. This was a free museum tour that focused more on the lumber industry's recovery efforts following the blast. It's educational elements focused more on the science of the lumber industry, the economic importance of the region's timber forests and how certain practices produced a faster return of the environment to productive levels.
There was a helicopter diorama that kids could climb in and feel like they were flying over the landscape. They also had a very nice outdoor playground. The museum was staffed by retired lumber workers who were both passionate and knowledgeable.
This was a nice stop before seeing the volcano up close. It also helped that Amy has taught the subject and was able to take what we were seeing and bring it into context. Plan about 1-2 hours at this stop, depending on how involved you want to get with the exhibits.
Also, an observation that may be lost on most visitors, was the subtle tension between the park service and the logging industry. Prior to the eruption, most of the land around Mount St Helens was privately owned by the logging industry. The creation of park lands was a significant reduction in their profitability.
While well presented, the basic presuppositions of the Forest Learning Center are at odds with the National Forest Service's programs. I would tend to lean more towards the preservationist side, but it is important to see the struggle that arises between business, preservation and science.