The Radersburg party was not alone in their experience with the Nez Perces. A few miles from where the bloody eruption involving Cowan and Oldham occurred on the Mary Mountain trail, another group was about to fare even worse in their meeting with a group of warriors from the caravan. The so-called Helena party of ten men included Andrew Weikert, Richard Dietrich, Frederic J. Pfister, Charles Kenck, John (Jack) Stewart, Leander Duncan, Leslie N. Wilkie, Benjamin Stone, and two youths, Joseph Roberts and August Foller, aged twenty and seventeen, respectively. Several of the party under Weikert had left Helena on August 13, reaching Mammoth Hot Springs on the twentieth, where they met the other members. Together, they started sightseeing two days later, visiting Tower Fall and traveling to Falls of the Yellowstone, near which they camped on the evening of August 23, at about the time prospector John Shively was being approached by the Nez Perces near Lower Geyser Basin. The next day was spent further touring the falls, and on Saturday, the twenty-fifth, the party crossed Alum Creek and passed up Sulphur Mountain enjoying the scenery as they headed toward the Mud Geyser. Late in the morning, from the heights about Sulphur Mountain, they observed the Nez Perce assemblage several miles to the south as it passed through Hayden Valley toward the Yellowstone, at first mistaking the throng for a herd of elk or a large group of tourists. "We could see something alive coming, but did not know what it was," stated Ben Stone. A mile or so farther, "on reaching the top of a small hill, [we] saw a large camp across the Yellowstone. Duncan exclaimed: Indians! Indians! My God, it's Indians!" [72] On discerning their identity, the Helena party hurriedly consulted and decided to remove their camp back from the falls and await the departure of the tribesmen. Stated Andrew Weikert: "We went into camp between the forks of the first creek [Otter Creek] above the upper falls, about a mile and a half above the falls, and felt quite secure." [73] Nevertheless, some of the party spent a restless night. [74]

On the twenty-sixth, two of the group, Weikert and Wilkie, rode out to see if the tribesmen had moved as the rest of the party lolled about camp. Evidently informed of the presence of the Helena tourists by the discharged soldier, James Irwin, whom they had picked up on the twenty-fifth, at least one scouting party of Nez Perces had mounted an effort to seek them out, doubtless to obtain whatever provisions they possessed. [75] Yellow Wolf's narrative, the only known Nez Perce source that touched on the subject, suggested that the party was led by either Kosooyeen or Lakochets Kunnin (Rattle Blanket). [76] In the afternoon, without warning, several warriors dashed into the camp firing their weapons. The attack was swift and caught everyone off guard, but they scattered nonetheless, running into the brush with the warriors in hot pursuit. As Ben Stone recalled, "Duncan sprang up like a deer and we were not long in following suit." [77] Frederic Pfister and Richard Dietrich ran off in the direction of the Yellowstone, but Dietrich failed to jump Otter Creek and landed in it, where he remained for several hours while the Nez Perces plundered the camp. Leander Duncan also ran into the woods and hid until dark and then started for Mammoth Hot Springs. John Stewart and Charles Kenck ran off nearly together, but the warriors wounded Stewart in the leg and hip and chased Kenck until they caught up with him, then shot him twice. Stewart heard Kenck cry out, then go silent. Shortly, one warrior returned and demanded money from the wounded Stewart, who turned over $263 and his silver watch. Unable to find Kenck or any others of the party, Stewart managed his way back to the camp after the warriors had gone, retrieved an overcoat, soaked his hip wound in the stream, and set out on what he expected to be an arduous hike to Mammoth Hot Springs. Soon, however, he chanced upon his own horse, but was unable to balance himself with no saddle. At Cascade Creek he washed his wounds and then moved on; after a mile or so, he encountered Ben Stone. At the initial shooting, Stone had run and somersaulted down the hill and landed in the stream, remaining hidden there for three hours while the warriors completed their raid. "I asked him if he was wounded," related Stewart, "and he said he was not. I told him I was, but whether badly or not I could not tell. I then asked him if he would stay with me and help me through to the Springs, and he said he would." [78] Together, they ate lunch and started down the trail.

Weikert and Wilkie, meanwhile, on returning from their lookout on Sulphur Mountain, ran directly into the warriors near the Yellowstone at the mouth of Alum Creek. The warriors were dismounted, and Wilkie had no trouble turning his mount and getting away. But as Weikert spurred his horse to follow, the Nez Perces fired at him, clipping his shoulder blade. Another bullet ripped into his gun stock. His horse stumbled and threw him, but Weikert was able to remount and escape with Wilkie. Both then raced up Alum Creek and circled through the timber back to the camp in an attempt to warn their colleagues, but on their arrival they realized that they had been too late. The warriors had taken their blankets, tents, and saddles and made off with fourteen horses. They had smashed several shotguns and burned whatever they did not want. [79] Provisioned with a ham found in the camp, Weikert and Wilkie started for Mammoth and soon overtook Stewart and Stone. With Stewart mounted on Wilkie's saddle horse and the lame Stone on Weikert's, the four men ascended and descended Mount Washburn and continued down the Yellowstone, gaining the hot springs shortly before 6:00 a.m. next morning, August 27. At McCartney's hotel they found their colleague, Frederic Pfister, who had reached Lieutenant Schofield's command near Tower Junction the preceding evening, within hours of the arrival there of Emma Cowan and Frank and Ida Carpenter. Pfister had gone back to Mammoth with Schofield's detachment, and on the morning of the twenty-seventh he started with the troops to Fort Ellis. An ambulance was summoned to transport the wounded Stewart to Bozeman, and he started down on Thursday morning, August 30.

Another of the Helena party arrived at Mammoth on the morning of August 27. Leander Duncan had also escaped the Nez Perce attack; he reported that Richard Dietrich was on the back trail two miles away, exhausted, and Weiker—this wound cleansed and dressed—rode out with an extra mount and brought him in. Dietrich refused to go down in the ambulance with Stewart, protesting that he could not leave until Joseph Roberts and August Foller were found. On Wednesday, the twenty-ninth, Weikert and hotel proprietor James C. McCartney started back to the Otter Creek camp to bury Kenck and to try to learn something of the whereabouts of the two young men. Next day they found and buried Kenck's body, but a search of the area through the thirtieth failed to disclose what had happened to Roberts and Foller, and on the thirty-first Weikert and McCartney headed back to Mammoth Hot Springs. (Weikert would later learn that Roberts and Foller had somehow escaped the attack and survived several days and nights until they reached the Madison Valley, where they ran into some freight wagons en route to Howard's troops and acquired food. Then they set out on their own for Virginia City, reaching that place without incident on August 31 where they erroneously reported the death of Ben Stone.) On the way, and within twenty miles of the springs, Weikert and McCartney engaged in a spirited encounter with eighteen Nez Perces who succeeded in dismounting them and driving them into the underbrush along the base of Mount Everts. [80] "The Indians never let up shooting, but kept picking up the dust all around me," recounted Weikert. "I think they must have fired fifty shots at me, but only cut a piece out of my boot leg and killed my horse." [81] Wilkie's horse spooked and ran off. Yet somehow eluding their pursuers, the men forded the Gardner River and walked the rest of the way into Mammoth. [82]

Exhausted from their ordeal, Weikert and McCartney arrived at Mammoth Hot Springs to find that the warriors had struck there. [83] On the thirtieth, Jake Stoner, an ambulance crewman who had remained behind at the springs, while hunting spotted a party of Indians near Lava Creek. Quickly returning to McCartney's place, Stoner warned Richard Dietrich and Ben Stone of the appearance of the Indians, and both men fled into the brush to hide. The warriors approached the cabin-hotel and searched around it. Ben Stone, who had retreated up a gulch to a wooded point of rocks behind the hotel, narrowly avoided the Nez Perces as they searched the area. But the Indians presently moved north beyond the park boundary toward Henderson's ranch, a complex established by James Henderson in 1871 and in 1877 managed by his son, Sterling, who provided mail service and provisions for area miners. (The ranch stood about six miles below Mammoth Hot Springs and two and one-half miles northwest of the present town of Gardiner and along the wagon road to Bozeman.) On the morning of August 31, when the Nez Perce scouting party of eighteen appeared at the ranch, five men were present—two at the house and three fishing in the Yellowstone some three hundred yards away to the east. Those at the house, John Werks and Sterling Henderson—observing the warriors' advance a mile distant—hurriedly gathered up arms and ammunition belts and raced to join those at the river: Joseph Brown, George Reese, and William Davis. Meantime, the Nez Perces split into two groups, a party of eight continuing the approach while the remainder stood their horses and watched from afar. The ranchmen assumed a strong defensive position among some boulders one hundred yards from the house and, as the eight warriors began emptying horses from the corral, let loose a volley of shots against them.

The firing spooked the Nez Perces' own animals, leaving the tribesmen dismounted and seeking cover behind the house and barn, from which they returned the fire. After two hours of sporadic shooting in which neither side gained an advantage, Henderson and the others withdrew to the river and crossed in a boat to the other side. The mounted warriors then came forward and sent a few bullets over the stream after them while the party at the ranch set fire to the log house, retrieved their own horses, and escorted the captured stock back toward Mammoth Hot Springs. No one was hit in the exchange, but as the warriors completed their withdrawal from Henderson's ranch, Lieutenant Gustavus C. Doaneen route with Company E, Seventh Cavalry, forty-two Crow Indian scouts, and a few wagons—coincidentally came on the scene, having seen a plume of smoke as he passed Cinnabar Mountain. The Doane party had left Fort Ellis on August 27, under orders "to push up the Yellowstone to the [Baronett's] bridge at the mouth of East Fork, cross that, and feel for the Indians up the right bank of the Yellowstone." [84] As Doane's column passed along the Yellowstone, numerous anxious citizens had attached themselves to the command. Racing after the Nez Perces, a detachment from Doane's command managed to take back nineteen of the stolen horses. [85] The warriors went back into the park. By then, Richard Dietrich, who was a music teacher in Helena, thinking it safe after the previous day's alarm, had returned to McCartney's place for food. As he stood in the doorway of the cabin, a Nez Perce warrior named Chuslum Hahlap Kanoot (Naked-footed Bull), still enraged over the loss of family members at the Big Hole, took aim at Dietrich and killed him. [86] A short time later, a detachment of ten men from Doane's command under Second Lieutenant Hugh L. Scott, guided by a local man, Collins J. ("Jack") Baronett, arrived to find Dietrich's still-warm body, which they removed to the floor of the cabin. "He had plunged forward on his face," remembered Scott, "and had been shot again, the bullet going the length of his body." [87] The warriors had started back up the Yellowstone River to rejoin the main camp. Trailing past the base of the Liberty Cap geyser cone, Scott's men pursued the warriors to Lava Creek and then, at Baronett's insistence, returned to join Doane at Henderson's ranch, where they bivouacked. [88] Following their skirmish with these same Nez Perces, Weikert and McCartney arrived to find Dietrich dead on the floor. With Ben Stone also missing and presumed dead, the two continued down the road to Henderson's. In fact, Stone had escaped the warriors' rush on the cabin on the thirtieth; his harrowing ordeal to elude the Nez Perces involved his hiding in the branches of a tree and an encounter with a bear before he, too, reached Henderson's ranch that night for a reunion with Jake Stoner, who had previously arrived there, and with Weikert and McCartney, who came in an hour after Stone. The next day, Weikert with some soldiers and citizens from Henderson's went back up the river to McCartney's hotel to bury Dietrich in "an old bath tub," for they had no lumber for a casket. Six weeks later, Weikert returned to Mammoth Hot Springs and exhumed both Kenck and Dietrich for reburial in Helena. [89]