1913: Alidades were established at three observation points along the summit.
April 17, 1923: "Arrangements are being made to erect a forest fire lookout house on top of Mount Hebo. The materials are on hand and the work will start at once said the supervisor." (Morning Register)
June 19, 1923: "A lookout house is being erected on top of Mt. Hebo, in the Siuslaw national forest in Tillamook county and several miles of trail and telephone line are being built, extending east from Hebo ranger station, according to Ralph S. Shelley, supervisor of this forest, who has just returned from a trip to that section of his district. L.E. Garwood, ranger there, has charge of the erection of the lookout house and it is expected to have it completed by July 1, said Mr. Shelley. Three miles of trail and ten miles of telephone line will be built this year with money available, he said." (Morning Register)
June 20, 1923: "A lookout house is being erected on top of Mount Hebo, in the Siuslaw national forest in Tillamook county, and several miles of trail and telephone line are being built, extending eastward from Hebo ranger station. Three miles of trail and 10 miles of telephone line will be built this year." (The Morning Oregonian)
1924: A cupola style lookout was constructed on the northeast summit, and a 30-foot tower erected on the southwest summit.
February 22, 1934: Panorama photos taken by Robert Cooper. (4S-9W-13)
March 8, 1934: Panorama photos taken by Robert Cooper. (4S-9W-23) (LOT)
March 10, 1934: Panorama photos taken by Robert Cooper.4S-9W-15) (West Point)
September 28, 1936: Panorama photos taken. (4S-9W-13) (East Point)
December 1936: "On Mt. Hebo a new lookout tower and house has recently been completed." (The Salt - Forest newsletter)
1937: A 53-foot tower was erected on the eastern summit.
1950: A 67-foot treated timber tower with an L-4 cab was constructed on the northwest summit.