August 17, 1917: "A.G. Jackson, of the educational department of the Forestry Service, returned yesterday from the Snoqualmie forest, in the Puget Sound country. Mr. Jackson visited Granite Mountain lookout and the campgrounds at Denny Creek, on the Sunset Highway. These grounds, which are comparable to the Eagle Creek campgrounds on the Columbia River Highway, are now in process of improvement. They lie close to the noted Snoqualmie Pass." (Oregonian)
June 1918: "Mr. Merritt, of the Portland office, and Mr. Smith visited the Granite Mountain lookout station and the Denny Creek campgrounds on May 14 and 15." (Six Twenty-Six)
September 1924: "The new lookout house on Granite Mountain is finished and it is a beauty." (Six Twenty-Six)
1924: D-6 style lookout house.
December 1924: "The material for the new lookout house was cut from regular mill stock by the carpenter prior to packing it to the lookout site. In order to correct a problem of snow blowing into the house, a new product from Weyerhaeuser, Balsam Wool, was used as additional insulation. The shutters were hinged from the top of the window frames, when open, they were propped up by rods creating a sun shade." (Six Twenty-Six)
Activated: April 23, 1942; Deactivated: September 22, 1943. Seattle Filter Center.
1956: A L-4 cab was built atop a 10-foot timber tower.
July 18, 2017: "An Army Special Forces unit based in Washington state managed to include a punishing workout and an assist to the U.S. Forestry Service as part of its recent change-of-command ceremony. Three dozen soldiers with Headquarters and Headquarters Detachment, 4th Battalion, 1st Special Forces Group (Airborne), carried 880 pounds of lumber along a 4.3 mile trail to the top of Granite Mountain (elevation: 5,633 feet) as part of the July 7 ceremony, in which Capt. Wesley Wiblin took over for the outgoing boss, Capt. Joseph Bresnahan, according to a unit spokesman." (Military Times)