Tsuga mertensiana 'Glacier Peak' is a relatively fast growing, irregular upright selection of Mountain hemlock with short, stout branches and attractive grayish Blue needles, densely radiating about the stems. According to Iseli nursery, the general effect in the garden is a rugged, yet tufty appearance. After 10 years of growth, a mature specimen will measure 10 feet (3 m) tall and 8 feet (2.5 m) wide, an annual growth rate of 6 to 8 inches (15 - 20 cm). This cultivar originated as a seedling selected by Iseli nursery of Boring, Oregon, who named it in honor of the glacier-capped Cascade mountains of Washington and Oregon. Planted in March 2021. Picture taken December 2021.
Ashamedly , I didn’t know of Glacier Peak’s or the mountain hemlock’s existence until last year. I’ve lived a total of 29 years in Washington state. Glad I have this beautiful tree now to remind me to think outside of my own little world.
The Iseli site actually does not say anything more (about the history of the cultivar) than "Iseli introduction" and "seedling selection". Except for the implication of the phrase "seedling selection" being that it appeared in a batch of seedlings raised at Iseli a body might think it came from Glacier Peak.