This used to be the site of the old Snohomish Junior High. When it was being built a few of us decided to check out the construction and play hide and seek. Suddenly we heard some teachers talking so we took off through the gym and ran out to the swampy area. One of my goofy friends pulled the fire alarm on the way out of the building. Naturally the police were called. We got away, but when we returned to get my car (that was known by the cops) we were stopped and talked to about the incident. I don't recall getting in much trouble but I sure wouldn't recommend doing something like that today!
Time goes on, the junior high is long gone and now the Snohomish Aquatic Center is heavily used by area swimmers, so use stealth when looking for this cache.
Congratulations to MaddiesDaddy on another first to find.