Erigeron pallens is a relative rarity that occurs on rocky alpine slopes in Alberta, BC, in the western part of the former District of MacKenzie, the Yukon, and Alaska (Moss & Packer). It's also known as Erigeron purpuratus ssp. pallens.
I've only come across one of these so far, in the one of the highest elevation, and barrenest, places we hike. It doesn't seem that there are many photos of it available, so I invite you to feast your eyes on this little beauty! Who knows when any of us may come upon it again?