Anyone on this forum live in Salem during the late 70s, early 80's?

I grew up (well, older) in Salem and spent every minute I could fishing Mill Creek and the Bluegill pond at Cascade Gateway Park. I went there a few months ago and it would appear the area that was designated for swimming is now the back yard to an RV park. Does anyone know what year they pulled the plug on the beach and swimming at the far end? The last time I was there was probably '77 or '78, prior to this last visit. I also remember they used to have a lifeguard and pumped in what I thought was clorinated water at the time from pipes that layed on the bottom. Thanks in advance for any info.