Glyphosate used in Twilight Lake?

After a 600 mile drive and a couple portages, I finally arrived at Twilight Lake in the Big Island Wilderness. First thing that greeted me at the campsite was a paper stapled to a tree stump saying Glyphoste (Roundup) treatment had been applied to the lake. I wish there had been something posted at the Byers Lake trailhead where I entered, it would have saved me some energy. I know many lakes in Michigan are treated this way but I did not expect it at a backcountry wilderness area lake. And I’m sure many here will say it’s absolutely harmless and I’m a treehugging crybaby……maybe, I’m also a Vet and lifelong outdoorsman. Anyway, even though it was past the timeframe posted to not use the water, I chose to limit my consumption. Only used enough to hydrate that evening and make coffee in the morning. Then I portaged out. Beautiful place but a bit of a bummer.