Preparations for the survey On February 10, 1853, outgoing President
Millard Fillmore signed legislation creating the
Washington Territory. On March 17, newly inaugurated President
Franklin Pierce appointed one of his supporters,
Isaac Stevens, to be
Territorial Governor of Washington Territory. The
Senate confirmed the appointment the same day. Stevens knew that on March 3, 1853, Congress had appropriated $150,000 ($ in dollars) to survey railroad routes across the
Pacific Northwest.
Secretary of War Jefferson Davis was eager to complete the surveys, which he believed would show a northern route to be impossible. This would force Congress to survey and fund the construction of a southern route, which in turn would lead to rapid development of the area and the creation of new
slave-holding states (as permitted under the
Missouri Compromise). Davis was determined to move as swiftly as possible on the surveys, and on March 25, 1853, appointed Stevens to lead the survey project. The Stevens survey was the first transcontinental survey of the western United States since the
Lewis and Clark Expedition of 1804–1806, and considered very important by the United States government. Stevens largely had his pick of men for the survey project, and chose a wide range of common soldiers, laborers, topographers,
engineers, doctors,
naturalists,
astronomers,
geologists, and
meteorologists.
Private Gustav Sohon also served with the group.
Captain John W.T. Gardiner of the
1st Dragoons (cavalry) was appointed the chief officer of the group. Mullan was assigned to the Stevens survey party as a topographical engineer. That Mullan, only recently arrived in San Francisco, would be ordered to join the Stevens survey is not unusual, as members of the team were drawn from all over the United States. Mullan traveled east to the town of
St. Louis, a booming town in the state of
Missouri. On May 10, while in St. Louis, Mullan was promoted to
2d Lieutenant and assigned to the
2nd Artillery Regiment. Mullan now met with Stevens, Capt. Gardiner, and
Lieutenant Andrew J. Donelson Jr. of the
Army Corps of Engineers. Stevens, who arrived in St. Louis on May 15, 1853, met Mullan and instructed Donelson to take a party to
Fort Union (at the confluence of the
Missouri and
Yellowstone rivers near what is now the
North Dakota/Montana border about from
Williston, North Dakota) and establish a
supply depot there.
Fort Union and Fort Benton Donelson booked passage on the
steamboat Robert Campbell for the trip. He and Mullan had interior cabins (which cost $100 each, or $ in dollars), while the six sappers slept on the deck (at $47 each, or $ in dollars). The Donelson/Mullan party left St. Louis on May 21, and arrived at Fort Union on July 3. During the trip, Mullan made meteorological observations whenever the ship halted. Mullan also assisted Donelson in mapping the territory the ship passed through from
St. Joseph, Missouri to Fort Union. During this trip, Mullan met his first
Native Americans, members of the
Eastern Dakota tribe. The
Robert Campbell deposited Donelson, Mullan, and their supplies at Fort Union. While at Fort Union, Donelson led Mullan and 11 other men on an exploration of the nearby country. Departing the fort on July 12, they traveled up
Big Muddy Creek, then proceeded due east to the
White Earth River. They went down the White Earth River for before paralleling the Missouri River for another to reach Fort Union again. Stevens departed St. Louis for
St. Paul, a small town in the
Minnesota Territory, on May 23. He and the majority of the survey party left St. Paul on May 28, and extensively mapped the region along what is now
Interstate 94. They finally reached Fort Union on August 1. On August 9, the reunited survey party left Fort Union. Stevens originally intended for Donelson and Mullan to lead a party north along the Big Muddy to its headwaters (near modern
Plentywood, Montana) before heading west along the border with Canada before turning south to reach
Fort Benton—the highest navigable point on the Missouri River. He intended for the main body of the Stevens survey to travel slightly up the Missouri until it reached the
Milk River. The main body would then follow the Milk River to a point near present-day
Havre, Montana, before heading south to Fort Benton. Traveling on the north bank of the Missouri, the united survey team crossed the Big Muddy on August 11. Then Stevens changed his mind, and decided the entire party should travel together along the Milk, with only small mapping parties sent off at various points to briefly explore the surrounding land. The group reached Fort Benton on September 1. During the trip, Mullan made topographic and meteorological observations.
Mission to the Salish On September 9, Stevens sent Mullan on a peace mission to the
Salish nation. Mullan was instructed to convey the peaceful intentions of the government of the United States, implore the Salish to make peace with the
Piegan Blackfeet, and express the desire of the United States to build up the settlement at
St. Mary's Mission. Mullan was also to obtain several guides from the Salish, and to explore any nearby passes through the
Rocky Mountains. Survey party aide F.H. Burr, three local men, a hunter, and a Piegan Blackfeet guide named White Crane accompanied him. Mullan traveled south from Fort Benton along Shonkin Creek, west of the
Highwood Mountains. Skirting the
Little Belt Mountains by driving southeast, he crossed
Arrow Creek, passed south through the
Judith Gap (the
Big Snowy Mountains to the east, the Little Belts to the west), and crossed several tributaries of the
Judith River. Reaching the
Musselshell River, he explored along its banks up and down stream for several miles, before striking south and finally finding the Salish encampment about south of the river. On September 18, Mullan encountered about 50 lodges of Salish and 100 lodges of
Kalispel, who received him very warmly. At one point during the meeting with the Salish, Stevens found himself without his interpreter. But after realizing a few Salish spoke French, Stevens was able to converse with them (having studied French for two years at West Point). The Salish chief agreed to consider the goodwill message, and sent four of his men back with Mullan as guides to the mountain passes. Mullan and his companions then returned to the Musselshell, where his Piegan Blackfeet guide left him. The Mullan party followed the Musselshell's north branch to the west-northwest, then continued to the
Smith River. They followed the Smith through the
Castle Mountains until they reached the Missouri River. The Salish guides knew the area well, and led him across the Helena Valley to Prickly Pear Creek. He crossed the
Continental Divide on September 24 via "Hell Gate Pass", and descended the other side into the valley of the
Little Blackfoot River. Essentially following what is today
U.S. Route 12 and
Interstate 90, he followed the river and its successor streams northwest to the Missoula Valley (entering near present-day
Hell Gate, Montana), then proceeded south through the
Bitterroot Valley to reach
Fort Owen (near present-day
Stevensville, Montana). There he rendezvoused with the main Stevens survey party on September 30, 1853.
Fall of 1853 exploration of the Bitterroot Valley On October 6, 1853, Mullan traveled from Fort Owen north to the mouth of Hellgate Canyon, where he rejoined Stevens (who had moved there some days earlier). The railroad survey was now over budget and behind schedule, and Stevens still needed to take up his duties as Territorial Governor in the territorial capital of
Olympia. Stevens resolved to proceed further westward, while assigning Mullan the task of mapping western Montana with the goal of determining the best route for a railroad. Mullan was also to take meteorological observations, gather data on river and stream flows, find the headwaters of the
Missouri River, and gather as much statistical data on population, wildlife, timber, agriculture and geology as he could. On October 8, Mullan left Fort Owen for a spot about north-northwest of present-day
Corvallis, Montana. He and 15 men set up a camp here in just seven days, erecting two barns, a corral, and four log cabins. Mullan named it Cantonment Stevens. On October 15, he and guide John Owen (owner of Fort Owen) set out to explore the southern end of the Bitterroot Valley and then proceed southward to find their way to
Fort Hall (near present-day
Pocatello, Idaho). But Owen lost his way after just a few days, and the two returned ignominiously to Cantonment Stevens. In November, Mullan, accompanied by five men, explored the
Bitterroot River to its source, crossed the
Sapphire Mountains and
Anaconda Range, and explored the
Big Hole River north and west to the
Jefferson River. Returning to the Missoula Valley, from November 28 to December 13 he retraced his route to the Big Hole River, followed it south to its headwaters, then crossed the
Beaverhead Mountains to enter modern-day Idaho. Passing south via the valley between the
Beartooth Mountains and the
Lemhi Range, he reached
Fort Hall on December 13. On December 19, he struck north again, retracing his path. He crossed
Monida Pass, then turned east after crossing the Beaverhead Mountains, passing through a broad prairie between the
Pioneer Mountains and the
Ruby Range. He followed the
Beaverhead River to the Jefferson River again, then explored the Gallatin Valley before turning west to the Big Hole River again. Turning north, he followed a stream until he reached a series of low ridges which divided the Big Hole tributary from the Hellgate Fork of the Bitterroot River. Crossing these, he arrived at the headwaters of the Deer Lodge River (now known as the
Clark Fork River) on December 31. He followed the Deer Lodge River to the Hellgate Fork, and retraced his path back to Fort Owen, which he reached on January 10. Mullan and his men had traveled through heavy snows and strong winds that drove the
wind chill tens of degrees below zero, crossed rivers and streams covered in thin ice (through which their horses frequently plunged), and often went hungry. They had crossed the Continental Divide four times in the dead of winter, had identified two wagon routes from Fort Hall to Fort Owen, and seen
Beaverhead Rock (which, in 1805, had told the
Lemhi Shoshone teenage girl guide
Sacagawea that she and the Lewis & Clark Expedition were near her homeland). In 45 days, he had traveled more than .
Blazing the Fort Benton-Mullan Pass road In February 1854, Mullan learned from Native Americans of a much better pass between the Missoula Valley and the Helena Valley. On March 2, he left the Missoula Valley with five men, one of whom was Private
Gustav Sohon. Mullan retraced his route along the Little Blackfoot River and over "Hell Gate Pass", and followed the Missouri River north to Fort Benton, which he reached on March 12. Obtaining soldiers, wagons, and supplies, he departed on March 14 and scouted out a level prairie road from Fort Benton to the confluence of the
Sun and Missouri rivers (at present-day
Great Falls, Montana). Rather than follow the route taken by Stevens a year earlier, he stuck to the Missouri River, which offered a flat road at least to the
Dearborn River. He then decided to strike inland rather than keep to the river, and discovered a wide, flat prairie about west of the river. This allowed him to skirt the rugged
Adel Mountains Volcanic Field. He then followed the valley of Little Prickly Pear Creek back to the Missouri River. On March 21, he camped on Prickly Pear Creek in the foothills of the
Lewis and Clark Range. Following
Tenmile Creek and then Austin Creek, he discovered and then crossed
Mullan Pass. After taking Mullan Pass over the Continental Divide, he regained the valley of the Little Blackfoot River and reached the Missoula Valley on March 28. Although the Mullan route was longer than the Stevens/Donelson route over
Cadotte Pass discovered in 1853, Mullan Pass had a gradual ascent and descent over only lightly wooded country that made it nearly perfect for the construction of a wagon road. Mullan had also crossed the pass in winter but encountered no difficulty with wagons. The importance of the Mullan Pass was immediately recognized by the press.
Exploring the Flathead Valley Mullan now sought a route west out of the
Flathead Valley to the plains of eastern Washington. On April 14, Mullan left Cantonment Stevens with four of his best men: Thomas Adams, W. Gates, Gabriel Prudhomme, and Gustav Sohon. Mullan followed the Clark Fork to its confluence with the
Flathead River. His party built rafts to cross the Flathead, and emerged onto
Camas Prairie on April 17. The party spent the night with the
Kalispel Indians, traveled north for two days, and spent the night with a band of
Yakama led by
Chief Owhi. Following the Flathead River again, the party reached
Flathead Lake. Mullan's group traveled north of the lake to try to find a way west, but could not. They turned south again on April 27. The party built a bridge to cross the
Tobacco River, and were forced to swim a tributary of the Tobacco at another point. A
Ktunaxa (Kootenai) Indian offered them hospitality on April 29 as the group followed the Tobacco River to its headwaters near the modern town of
Fortine, Montana. A day later they met Michael Ogden, a
Hudson's Bay Company agent who had established a temporary trading post in the vicinity of modern-day
Kalispell, Montana. Resting with Ogden for a day, the party continued south back to Cantonment Stevens accompanied by an Indian woman and her children. Reaching Camas Prairie, Mullan followed Hot Springs Creek to its source, rediscovering a series of
hot springs near present
Hot Springs, Montana, which Lewis and Clark had previously visited. Continuing to Cantonment Stevens, on May 4 the Mullan party found its way barred by the Clark Fork River. Two rafts were built in an attempt to cross the river, which was swollen with spring runoff. Prudhomme, riding his horse, crossed the river safely while guiding the other horses and towing one raft. But Mullan's raft, with the remainder of the group, was swept downstream. Mullan was cast adrift when the raft struck a
snag, and may have been killed by flotsam if his men had not abandoned their rafting poles to save him. Mullan now ordered Adams, Gates, and Sohon to strip naked and swim for shore, towing the raft behind them. The raft, now downstream, passed a rocky island. The men swam for the island, and pulled the raft close. Mullan's party now tried to save their supplies, and got most of them on the island before the raft broke free and disintegrated. Adams swam to the opposite shore through icy water, and made his way (still naked) to Prudhomme. Prudhomme then helped rescue the party and the supplies using the horses. After nearly losing the party, Mullan's group arrived back at Cantonment Stevens on May 5.
Final explorations With Native Americans either unwilling to talk, purposefully deceitful, or too unfamiliar with wagon travel to offer good advice, Mullan still needed to determine which of the remaining passes known to white explorers would be the best for a planned railroad or wagon road. On May 21, Mullan set out with a small party on horseback, following the Clark Fork. Reaching
Lake Pend Oreille, the group abandoned their horses and
canoed across the lake and down the
Pend Oreille River to the St. Ignatius Mission near modern-day
Cusick, Washington. A messenger was sent to John Owen, who had relocated to the
Spokane Valley, asking him to send horses to the mission. Meanwhile, Mullan and the remainder of his group traveled northwest about to
Fort Colville, a Hudson's Bay Company trading post located at
Kettle Falls on the
Columbia River. After purchasing supplies, the party returned to St. Ignatius. Consulting with Native Americans living at St. Ignatius, Mullan's group then went south to the Spokane Valley, and returned east by following the
Coeur d'Alene River into the mountains and crossing
Lookout Pass back to the Bitterroot Valley and Cantonment Stevens. Mullan reported to Stevens that flooding on the Pend Oreille route rendered it less feasible than the Lookout Pass route. Mullan then explored the last remaining route for a roadway: Following Lewis and Clark's trail over
Lolo Pass. Mullan and his party left on September 19, leaving the Bitterroot Valley by cutting westward where
Lolo Creek meets the Bitterroot River (near present-day
Lolo, Montana). For , the wide Lolo Creek Valley provided easy going. The route over Lolo Pass, however, was steep and blocked by much fallen timber. The party passed
Lolo Hot Springs (first identified by Lewis and Clark), and then followed the
Lochsa River to the Middle Fork of the
Clearwater River (then called the Kooskooskia) and the way out of the mountains. After 11 days of very difficult travel, Mullan's group emerged onto the
Weippe Prairie and continued following the Clearwater—intent on following it until it reached the
Snake River. From there, the party could easily orient itself and travel to
Fort Walla Walla. About from the Clearwater's confluence with the Snake, Mullan's group struck south up the valley of Lapwai Creek. After a few miles, he came upon the farmhouse of noted fur trader and frontiersman
William Craig. Craig, his wife, and the local
Niimíipu (or Nez Perce) people fed the group fresh vegetables, the first the group had eaten in 21 months. Mullan's party spent the night at the Craig farm, and then cut overland west to Fort Walla Walla. The party reached Fort Walla Walla on October 9, and then
Fort Dalles on October 14. Having surveyed all known routes, Mullan wrote a final report to Stevens advising that the future military road utilize Lookout Pass. He was then discharged from the Stevens survey party, and returned to Army authority. ==Interregnum of 1855 to 1858==