Listed as post no. 227 in Ernest Voorhis [1859–1933], “Historic Forts” [1] :

Originally this was a North West Co. fort on the north bank of Peace river at the mouth of Middle river. Built by Simon Fraser 1805 as a base for his British Columbia explorations. It was known as “Rocky Mountain House, or Fort”, also as “Old Hudson’s Hope”, and “Rocky Mountain Portage Fort”. This post was operated by the Hudson’s Bay Go. after the coalition of 1821. I was abandoned for a time in 1825 to punish the Indians for the massacre at St. John in 1823. New Hudson’s Hope was built about 1875 on the south bank about 12 miles further upstream from Old Hudson’s Hope, at the east end of the portage, near east end of Cañon at its foot. Sometime after 1880 this post was again moved to its present location on the north side. Harmon in his journal 1810, October 15th, calls Hudson’s Hope the “Rocky Mountain Portage Fort”. Cust’s House and an old Hudson’s Bay Co. post are shown on Arrowsmith map 1832 (No. 100) at the west end of the portage from Rocky Mountain House. The location of the original fort is shown on the Dawson map 1879 (No. 81) and marked “abandoned”.

Post no. 3 in “Historic forts and trading posts” by Ernest Voorhis [1859–1933]:

The Hudson Bay Co. house adjoining the North West Co. house called Rocky Mountains House, on North Saskatchewan river near mouth of Clearwater river. Name Acton house was given to distinguish it from the North West Co. house, but it was generally called Rocky Mt. House [1].

Five fur trading posts were known as Rocky Mountain House near the same site as present-day Rocky Mountain House. Rocky Mountain House is post no. 467 in “Historic forts and trading posts” by Ernest Voorhis [1859–1933] :

North West Co. post on North Saskatchewan river, 1-1/4 miles above mouth of Clearwater river, 3 miles below Hangman’s tree (1790) on north bank of river, 70 yards from river’s edge. It stood on high bank, well adapted for defense as block-houses commanded the fort. Of exceptional strength being in territory of Blackfeet Indians. Hence it was sometimes called “Blackfeet post.” Built by John McDonald of Garth in 1802, although the first structure was erected in 1799. It was visited by David Thompson in 1800 and 1806 and by Alexander Henry Jr. in 1811. It was the uppermost permanent post of the North West Co. on the Saskatchewan river. Ruins were still visible in 1886. After union of the two companies it was occupied by the Hudson’s Bay Co. for many years and finally discontinued in 1875.

The Hudson’s Bay Co. constructed a fort nearby (about 114°59′ w. & 52°22’ N.) called Acton House or Rocky Mt. House, both names being given on some maps. [1]

Archaeologists at the Rocky Mountain House National Historic Site have identified four fur trade post:

Rocky Mountain House of the North West Company, built in 1799.
Acton House of the Hudson’s Bay Company, also built in 1799.
Rocky Mountain House, the Hudson’s Bay Company post of 1835-1861
Rocky Mountain House, the Hudson’s Bay Company Post of 1868-1875.
They searched for the fifth post, but it stood where the river runs now. The Hudson’s Bay Company built this temporary post (1865-1868). It housed fur traders and their families until the last post was finished.

Voorhis notes that there was also a North West Company fort on the Mackenzie River called Rocky Mountain House, built in 1800 and soon abandoned. The following forts were also called Rocky Mountain House: Jasper House (No. 245), Hudson’s Hope (No. 227), Acton House (No. 3), Henry’s House (No. 218).

Listed as “Henry’s House (1),” post no. 218 in Ernest Voorhis [1859–1933], “Historic Forts” [1]

Post built by William Henry 1812 on upper Athabaska river near confluence of Snaring river, about 8 miles below Jasper House village of today and about 20 miles above the last site of Jasper House, about 8 miles below confluence of Miette river. It was used as an outpost of Jasper House and was deserted about 1861.

North West Co. fort at north end of lake McLeod, British Columbia, built by Simon Fraser for the Company in 1805. This is said to have been the first post erected in B.C. After the union of 1821 this post was operated by the Hudson’s Bay Co. to date.

— Ernest Voorhis [1859–1933], “Historic Forts” [1]

North West Co. fort at east end of Fraser lake, B.C., built by Simon Fraser 1806. It was burned, October 4, 1817 and afterwards rebuilt. It was taken over by the Hudson’s Bay Co. after the union of 1821 and was operated by the Company until about 1900. It appears on all the Lists of forts to 1894. This fort is said to be “The first settlement made in the so-called Oregon Territory by civilized man”.

— Ernest Voorhis [1859–1933], “Historic Forts” [1]