Jim,
I discovered the wild Lily Patch some years ago and knowing that our Cyp acaule in Pennsy always bloom together with them, I then took a closer look. I almost flipped my lid when I saw them .
I have been tracking them now at least 7 years. They have shifted a bit upwards on their slope, but they have not diminished in numbers. Imagine, this is right on a bike path. I am happy nobody sees them, or they would surely be gone by now.