Inter Glacier. On the northeast slope. It was named by Major E. S. Ingraham in 1886 when he attempted but failed to ascend the mountain from the north side. The name was suggested by the glacier being hemmed in by a rim of rocks.
Ipsut Pass. In the northwestern corner of the Park. Flowing from it to the Carbon River is a stream called Ipsut Creek. The word is said to be a form of an Indian word meaning "bear."
Iron Mountain. On the southwestern slope of the mountain, overlooking Indian Henrys Hunting Ground. The name describes the masses of supposed iron stain. Elevation, 6,200 feet above sea level.
Jeanette Heights. On the west-central slope overlooking Edmunds Glacier. Origin of name not ascertained.
Josephine Creek. A tributary of Huckleberry Creek, taking its rise in Green Park. Origin of name not ascertained.
June Creek. Flows across the boundary in the northwestern corner of the Park. Origin of name not ascertained.
Kautz Glacier. This glacier begins at the foot of Peak Success, the southern summit. It was named in honor of Lieutenant (afterwards General) A. V. Kautz, who attempted an ascent in 1857. The creek flowing from the glacier bears the same name.
Klapatche Ridge. Near the west-central boundary of the Park, between the North Puyallup River and St. Andrews Creek. Origin of name not ascertained.
Knapsack Pass. In the northwestern portion of the Park, a pass between Fay Peak and Mother Mountain from Mist Park to Crater Lake.
Kotsuck Creek. Flows across the east-central boundary of the Park. Origin of name not ascertained.