I second Bruce's opinion about the Elk Pass Ponds, there's a lot worse out there to filter from.
As far as the FL Falls go, you can't see them but you sure can hear it from the Gill Brook Trail. Listen for it where the trail to Colvin splits from the GBT. Head straight down the hill, and come to the headwaters of Gill Brook. You can do what I did and cross the brook and follow the noise of the falls. There's a 1/8 mile strech of thick spruce forest to negotiate, and some nasty sod traps that will suck you in up to your waist.
If I go there again, I think I would hit the first brook, follow it downstream for about 100 yds. to where the brook from FLF joins it. Then follow that brook upstream to the falls. There's blowdown to fight with, but I think it would be alot less taxing than trying to negotiate the spruce forest and the dreaded sod traps.
The falls have to be roaring this time of year with all of the rain we've had. It is quite a site. Good luck and take pictures.
Tom