Yep Dan, I love brookies. They're not native to the west but they are plentiful. I remember one morning catching 7" to 9" brookies right at our campsite on the upper reaches of the Big Hole River and putting them straight into the frypan. My buddy Don and I would switch off casting and cooking and ate until we were stuffed, we even caught a few beautiful grayling that morning which we carefully released.
Yellowstone Park is full of them as well, especially at higher elevations. While hiking to a back country lake in the North Central section of YNP we came across a beaver dam on a side channel of the river we were following and immediately we thought Brook Trout. Brookies can grow large behind beaver dams with the concentrated forage in the slower water and we caught a bunch of 12-14" kamikaze fish on big bushy dry flies. It's moments like that that partially make up for those frustrating days dealing with finicky trout at lower elevations. Came back a couple of years later and the dam was gone.
Most of the brookies I've encountered out west are small (9-10" at most) are easily fooled with attractor dry flys and are most consistently found close to the headwaters of rivers. And they are the prettiest trout I've seen. I understand they grow quite large in eastern Canada.