Also referred to as the Yellow-Leaved Iris or Iris chrysophylla. But may be a Tough Leaf Iris? This map shows Iris tenax to be something one would be more likely to see in this area. Definitely a first for me since lupines generally reign supreme in the purple department, seen around Memorial Day. — Ritzville, WA.
I spotted a clump of Flag Iris (?) over in the Columbia National Wildlife Refuge this spring as well.