Before rejoining Isaac Stevens’s narrative of 1853, I want to share a little information. The surveying team was about reach the “débouché of Hell-Gate”. “Hell-Gate” known as “Hells Gate” to us today, “lies on the river bottom left over from the great ice age floods about 15,000 years ago. At the south end of the park are basaltic columns from the Pomona flows 14 million years ago. Hells Gate State Park was once the site of a Nez Perce Village. Little is left of the village, but depressions south of the campground are the remnants of pit houses used for years by the Nez Perce as they fished for lamprey near Asotin Creek.”  The term débouché means an opening or a passage, not necessarily an established path or road.
As the purpose of this series is to share Stevens’s journey with you, I tend to offer fulsome quotations because his writings are often rich with imagery. Much of the narrative deals with geographic details and their amenability, or not, to a railroad system.
September 27, 1853. We soon entered “the Cañon - not, properly speaking a cañon, for throughout its extent, until you reach the debouche of Hell-Gate, there is no special difficulty on the trail, nor would there be excessive work to open a good wagon road. But good many sharp spurs come down close upon the river, throwing the trail well back, or involving a crossing of the stream to avail one’s self of the prairies invariably found opposite each of these spurs. Much of the country was of a very excellent description, abounding in timber, well watered, and with soil of an excellent quality.…Emerging from the cañon we come into a wide, open valley commencing half a miles before reaching the mouth of the Blackfoot [river], continuing down the valley of the Hell-Gate until we enter the Hell-Gate ronde, a large, extensive tract of many miles in circuit, where the Hell-Gate joins its waters to the Bitter Root. Though not mentioned, at some point they camped for the night.
September 28, 1853. An early morning start was made along the west bank of the Bitter Root river and they crossed two streams. One was called “Traveller’s Rest creek” and had been used and named by Lewis and Clark. They traveled a little over twelve miles and crossed the Bitter Root and encountered “some Indians from Fort Owen” as well as Lt. Arnold. They reached Fort Owen about mid-day, joining Lt. Arnold’s team as well as Mr. Lander.
“Mr. Lander’s Trip” Lander had been instructed to depart at once to examine the approaches to the mountains. He ran a line from his camp at Marias to the Teton, to Sun River, crossing the river at the “island some six miles below the forks. “Between the Teton and Sun river he killed the first grizzly bear, near a lake named, in consequence, Grizzly Bear lake.” (Stevens 1853) Lander’s line work continued from the Sun River to the upper waters of the Dearborn, then immediately under the foot-hills of the Rocky Mountains to Lewis and Clark’s Pass (named for Lewis’s return trip). He continued over passes, through waterways and valleys; all the while, his team taking various measurements, readings, and recording topographical information, and noting objects, flora and fauna. They traversed through some rather harrowing narrow Indian trails and rocky passes and steep descents. “In consequence of the route taken by Mr. Lander, and his animals having been much pushed, they came in [to Fort Owen] exceedingly jaded, although he started with the best train of the whole party. He was unable to make any observations whatever bearing upon our railroad line, excepting for seven miles of the divide…”
“GR Plate 30. “Fort Owen - Flathead Village” by Del Stanley
Fort Owen (see sketch) is situated on the Scattering creek of Lewis and Clark; and I would earnestly urge all persons desirous to know the minute details of the topography of this valley to study carefully the narrative of Lewis and Clark; for us it was the matter of the greatest gratification, with their narrative in hand, to pass through this valley and realize the fidelity and the graphic character of their descriptions.
Stevens spent a brief few hours reviewing their rations and the condition of their animals. While rations were plentiful, the animals were weary and none of them would “continue to be serviceable for any considerable length of time, and I believed they would be entirely equal to any service which Lieutenant Mullan’s duties might require of them.” Stevens did not illuminate what Lt. Mullan’s duties were and what duties the animals might have to perform.
September 29 - October 3, 1853. During these days we were all occupied in making arrangements for the movement of the parties westward, and to establish Lieutenant Mullan’s winter post. Lieutenant Donelson arrived on the 29th with the main party, and Lieutenant Mullan on the 30th with a delegation of chiefs from the Flathead nation.
 Idaho Department of Parks and Recreation. “Hells Gate State Park”. Hells Gate State Park | Department of Parks and Recreation (idaho.gov). Accessed 2/26/2022.  “Narrative of the Final Report of Explorations For A Route For A Pacific Railroad”, Isaac Stevens, Page 121.  “Narrative of the Final Report of Explorations For A Route For A Pacific Railroad”, Isaac Stevens, Page 122  Ibid.  Ibid. Page 123
Idaho Department of Parks and Recreation. “Hells Gate State Park”. Hells Gate State Park | Department of Parks and Recreation (idaho.gov).
Stevens, Isaac I. “Narrative of the Final Report of Explorations For A Route For A Pacific Railroad, Near The Forty-Seventh and Forty-Ninth Parallels of North Latitude, From St. Paul to Puget Sound, by Isaac I. Stevens, Governor of Washington Territory, 1855”. Published in 1859 by the Secretary of War, Honorable John B. Floyd.