Yuma War The Yuma War was the name given to a series of United States military operations conducted in southern California and what is today southwestern Arizona from 1850 to 1853 . The Yumans were the primary opponent of the United States Army , though engagements were fought between the Americans and other native groups in the region . Conflict generally took the form of guerrilla warfare and over the course of three years , the army engaged in pursuing unfriendly natives , protecting American settlers crossing the Colorado River and preventing conflict between the native tribes . A peace treaty in summer of 1853 was signed , ending hostilities between the Yuma and the United States , but it sparked a short war between the Yuma and the Cocopah . During the conflict , the historic Fort Yuma was constructed and became an important outpost on the frontier . War . Glanton Massacre and the Gila Expedition . The Yuman tribe was small compared to many other North American groups . On average a Yuman village consisted of around eighty to 250 men and women spread out along the far western Gila and southern Colorado Rivers . Following the Mexican Cession and the California Gold Rush , American settlers headed west and many crossed the southern portion of the Colorado River , through Yuman territory . To exploit this opportunity , the Yumas established a ferry near the confluence of the Gila and the Colorado Rivers to transport American settlers from Arizona to California . In early 1850 , California outlaw John Joel Glanton and his gang of twelve men attacked their Yuma ferry and occupied the area . They then robbed and murdered both Americans and natives as they traveled around and across the river . In response a Yuman war party attacked and massacred Glanton ' s gang , killing nine , only four escaped . Those killed were scalped and burned in a large bonfire . California responded with the Gila Expedition , raising a militia of 142 men , only raised when they were paid six dollars a day , to fight the Yuma instead of panning gold . Setting off on April 16 , the Gila Expedition entered what is today Arizona only to be defeated in September after a series of skirmishes . The expedition was a failure and due to the inflated prices caused by the gold rush , cost the State of California 113 , 000 dollars , a sum which nearly bankrupted the state . Establishing Fort Yuma . In November 1850 , United States Army Captain Samuel P . Heintzelman met with Yuman leaders at the Salton Sea to negotiate a peace . Apparently successful , the captain returned to Vallecitos where he began preparing for his new orders which were to establish a post at Yuma Crossing to protect the area from outlaws and hostile natives . The column , thinned by desertions of soldiers to the goldfields , left San Diego on October 3 , 1850 with about 100 men of the 2nd Infantry while a fourth company marched to build a post with a warehouse at Vallecitos , as a supply depot for the Yuma post . The expedition reached Yuma Crossing on November 27 , and began the construction of Camp Yuma , then just a camp of tents , a hospital and an orchard . American forces included ninety - two enlisted men , two officers and a medical officer for the hospital . Heintzelman ' s command was supplied via steamship from California , through the California Gulf and up the Colorado to the fort . This was difficult however due to the Colorado ' s strong current and by the time the steamships could make it all the way around Baja California , they had to manage the Colorado which took time . Thus the Californians had to rely on supplies sent overland , it was difficult as well but proved to be successful . After establishing a peace , Heintzelman reported that the Yumans along the Colorado were friendly . Supply difficulties began when supply wagons arrived late and did not carry enough to supply the troops for long . Supply by sea from San Diego had been requested but did nor arrive as planned . When it did arrive boats had difficulty bringing it up from the mouth of the Colorado against the river ' s strong tidal bore at the river mouth , strong spring flood current and the confused maze channels in the delta . Bringing it overland by wagon was difficult also but more successful . In October 1850 , U . S . Army Topographical Engineer Lt . George H . Derby was ordered to travel from California to the Colorado River to determine a supply route over water to Heintzelman ' s command . For his voyage , Derby was provided with transport by Captain Alfred H . Wilcox commanding the army transport schooner " Invincible " . They departed San Francisco on November 1 , 1850 . In December , after making it only thirty miles from the Gulf of California , the " Invincible " was unable to proceed up the river any further . Suspecting a problem and nearly out of food , Captain Heintzelman constructed a raft with sails to travel down the river , some sixty miles to the " Invincible " . With eight men and two civilians , the captain first sailed down the Colorado for three days before finding the " Invincible " , missing an anchor and ran hard aground . After some work trying to free the schooner , it was finally released and Captain Wilcox decided to offload his supplies onto the Sonora side of the river . The raft was too small to carry the provisions so Heintzelman directed First Lieutenant Edward Murray to cross into Mexico with a train of wagons to retrieve the supplies . Fortunately for the Americans , their little invasion of Mexico in January 1851 went unnoticed and the much needed supplies were brought to the fort . Later Heintzelman received instructions allowing him to send armed parties into Mexican territory for supplies but he was not permitted to pursue hostile natives across the river . Just after First Lieutenant Murray ' s return , nine wagons from across the desert arrived . The food would not last long though , in 1851 the crops of the Yuma failed so many found themselves traveling to the fort in order to beg Captain Heintzelman for food . In February 1851 , Heintzelman again met with some Yuman leaders along the Colorado . Presenting them with tobacco , food and other gifts , the Yumans were very pleased and expressed their fear of the Maricopa who lived along the Gila River and were raiding Yuman villages . Heintzelman attempted to secure a peace between the Yumans and Maricopa . Apparently he did not succeed as the conflict between the two tribes escalated until 1857 when the Pima and Maricopa nearly annihilated a force of Quechan raiders and their allies in the Battle of Pima Butte . Also in February , a colonel named Smith arrived at the camp with orders to survey an area on the Colorado ' s western bank for a permanent military base . They decided on a location just south of the camp at a place called Mission Hill , the site of the former Fray Francisco Tomas Garces mission . In April , natives suspected of being Mohaves raided the livestock pen of Fort Yuma , taking off several animals without resistance , also at this time , the Americans established communications with the Pima and the Mohave . Oatman Massacre . Doctor John De Conte arrived at the post from the east on February 21 , in his possession was a letter from Royce Oatman , the father and leader of an immigrant party traveling through Arizona along the Gila . In the letter , Royce described how much of his livestock had been stolen by hostile natives and he was nearly out of food and stranded with his family west of the Pima Villages . Heintzelman sent two soldiers with two mules packed with supplies to rescue the Oatman Party . But when they arrived after a 120 mile journey , all they found was two graves and an abandoned wagon . Captain Heintzelman later discovered that six people of the Oatman Party had been massacred , and two young females named Olive Oatman and Mary Ann Oatman were abducted . Their fourteen year old brother Lorenzo Oatman was thrown over a cliff but survived long enough to help rescue his remaining sister years later . At the time , the Americans believed Maricopas were responsible for the murders but later accounts suggest that it was either the Mohave or Yavapai to blame . The two young girls were taken as slaves and later sold to the Mohave tribe , Mary Ann died of starvation in captivity and Olive was ransomed five years later . Heintzelman blamed Doctor De Conte for not coming to the aid of the Oatman party and De Conte blamed Heintzelman for not sending an expedition , which would be a violation of the captain ' s specific orders . Siege of Fort Yuma . During the construction of the camp , there was no fighting between the Yuma and the American army due to the peace Heintzelman had concluded , but peace would not last long . Heintzelman occupied his time with mapping the area , noting the depths of the Colorado , and recording temperatures . The hottest it got according to Heintzelman was 121 degrees fahrenheit . Ultimately the problem of maintaining a post , surrounded by two vast deserts became untolerable so the Captain Heintzelman was ordered to withdraw his company in July 1851 for Santa Ysabel and then to San Diego . He left ten men and Lieutenant Thomas William Sweeny to guard the ferry . Their orders were to continue protecting the area from hostiles and to prevent immigrants from settling on Yuman soil . A day before departing , Heintzelman gathered some Yuman chiefs together where he informed them of the situation . Lieutenant Sweeny was an Irish immigrant who became a hero known as " Fighting Tom " during the Mexican War , he was also very disliked by Heintzelman and later led Irish rebels in the Fenian War . While at San Diego , some Yumans and Cocopahs arrived and requested that Heintzelman help them remove Chief Cavallo y Pelo and Santiago from power as they were not friendly with the army and wanted the peace to end . For months before , Heintzelman had heard rumors that Santiago was trying to unite the Yuma for a war against the United States but he was in denial , believing the Yuma only wanted peace . The captain informed the natives that he did not have legal authority to remove their chiefs so he advised them to return to their village and elect new chiefs as they saw fit . Unbeknown to Heintzelman , the Yuma were preparing for a siege of Fort Yuma . In October 1851 , a letter arrived at San Diego from Lieutenant Sweeny which asked that Heintzelman immediately send aid to the fort . Provisions were low , scurvy had broken out and dozens of Yuman warriors had surrounded the post . Sweeny expected an attack but Hentzelman ' s only response was a letter of his own stating that there was no reason to believe the Yuma were hostile . But when news arrived that four of Sweeny ' s command had been killed by around 800 Yumans , Heintzelman sent sixteen men under Captain Delozier Davidson with a train of mules and wagons . The squad arrived at the fort on December 6 but abandoned it soon after for a new camp six miles to the south near Pilot Knob . Garra Revolt . While Captain Davidson marched east , Heintzelman learned of a December 1851 Cahuilla and Cupeno raid on Warner ' s Ranch and Agua Caliente in the San Felipe Mountains . The Cupeno warrior Antonio Garra led what became known as the Garra Revolt . California ' s population was very panicked about the warfare being waged so close to their settlements on the coast , in San Diego concerned citizens began preparing to defend the town in case the Cahuilla and Cupeno attacked there . In response to the raids , Heintzelman started the Agua Caliente Expedition , a march to the San Felipe Mountains . Just northeast of Agua Caliente , Heintzelman ' s column of five infantry companies and one artillery company encountered 100 Cahuilla ' s , under Chief Chipule , at Coyote Canyon , located within Borrego Valley . A battle was fought on the morning of December 21 , 1851 , ending with the loss of six warriors , including Chipule and Chief Cecili . The natives were armed mostly with bows and they were routed from the field . From Coyote Canyon , Heintzelman continued northeast , further into the mountains , where they found a rancheria containing items from Warner ' s Ranch . The rancheria and nearby village were abandoned but Heintzelman had them burned before continuing back to Agua Caliente . After losing their villages , the Cahuilla ' s chose to surrender to the Americans . Jonathan Warner was used as an interpreter in a court case to decide the fate of four Cahuilla chiefs who were found guilty of raiding Warner ' s Ranch , killing civilians there , burning the place and robbing it . Subsequently the four , named Juan Baustista , Francisco Mecate , Quisil and Luis , were executed by firing squad and buried on December 25 , 1851 . Garra was captured at Razon ' s rancheria in the Coachella Valley , by the Mountain Cahuilla leader Juan Antonio and turned over to the volunteer company from Los Angeles . He was later tried and executed in San Diego , January 10 , 1852 . Campaigns along the Colorado River . Heintzelman then returned to San Diego where on February 8 , 1852 , he set out on the Yuma Expedition , to reinforce Fort Yuma . With 160 infantry and cavalry , Heintzelman arrived at the fort in March , only to find it nearly destroyed . All of the captain ' s personal belongings left at the post were missing or destroyed , the fruit orchards were withered and his raft sunk . Heintzelman was very upset and proclaimed in his book that Captain Davidson was a coward for abandoning the fort . Captain George Stoneman , who served with distinction in the American Civil War , commanded the American cavalry during this march . In the spring and summer of 1852 , United States Army operations against the Yuma were halted . Terrible sand and rain storms , combined with the heat , prevented Heintzelman ' s garrison from doing anything other than trying to cope with the weather . Relations between the Cahuilla and the Cupeno broke down in 1852 and the two tribes went to war . In February 1852 , the steamer " Sierra Nevada " made her way sixty miles up the Colorado , there they constructed two fifty - foot flatboat s to be used for transporting supplies . When the boats were finished they were loaded with provisions and sent north to the fort . One of the boats was swamped in the river and lost its entire cargo but it was refilled and eventually reached Yuma Crossing . The other boat was not as successful and had to offload its goods at Ogden ' s Landing far south of the fort . After this event , Heintzelman accepted that he would have to rely on supplies from overland . Captain Edward H . Fitzgerald was ordered to escort a supply convoy to the fort with forty dragoon s at his disposal . At camp in the desert , eighteen miles from Fort Yuma , Fitzgerald ' s herd of mules and horses was attacked . Defending the animals were eight soldiers and one civilian who fought the Yumas for eighteen hours . In the end all but one of the soldiers were killed while the Yumans suffered four dead . Captain Fitzgerald retreated to the fort , leaving his casualties behind , where he informed the garrison of his defeat . Captain Heintzelman organized a burial detail of sixty men and when they arrived at the San Luis battlefield , the bodies of the slain were found stripped and bady mutilated by buzzard s . Fitzgerald ' s defeat angered Heintzelman much , he requested from his superiors permission to attack the Yumas on the Arizona side of the river but it was denied . According to Heintzelman , the Yumas grew confident after the Battle of San Luis . In August , the schooner " Capacity " arrived off the Colorado ' s mouth and by September the ship was anchored where the " Sierra Nevada " once was . There they began construction of a sixty - five by sixteen foot paddle steamer named " Uncle Sam " . " Uncle Sam " was launched by November and on December 3 , it arrived at Fort Yuma and delivered thirty - two tons of goods . The American garrison celebrated the steamer ' s arrival , its skipper , Captain James Turnbull took Heintzelman on a cruise of the Gila and Colorado before he had to steam back down to the California Gulf . Late in March , the soldiers of Fort Yuma organized a second expedition of eighty infantry and cavalry under Captain Fitzgerald and Captain Davidson . It was not very successful , the Yumans were warned of the advancing Americans and they retreated from their villages without a fight . Only twenty Yumans were spotted by the soldiers and one old man was captured . Lieutenant Frederick Steele launched an operation just after , with forty men Steele proceeded up the western bank of the Colorado River and engaged in one skirmish . A small band of Yumans were found along the river and attacked as they fled across . Several Yumans were reportedly killed though most escaped harm . Lieutenant Steele continued on where he destroyed a few Yuman fields before returning to the fort . American civilians passing by the fort informed the captain that a large party of Yumans were together about forty miles north . Thirty men were sent to investigate but they returned to Fort Yuma after traveling seventy miles north without encountering the enemy . In mid May , the garrison conducted several scouting operations in the vicinity around the fort . In one of these missions , Lieutenant Sweeny with twenty - five men attacked a village south of Fort Yuma . There they killed one warrior , accidentally wounded a woman and burned the village . Large amounts of clothing and food were also destroyed . Lieutenant Henry B . Hendershott led a third party into Yuman territory around the fort , two villages were destroyed along with several wheat fields and two warriors were killed . During a forth operation of the same type , First Lieutenant George Pearce and his men killed three warriors and wounded Chief Pasqual . One woman was also wounded and a child drowned in the Colorado . Battle of the Gila River . Because of the bad weather in the July 1852 , only one scout was made by Lieutenant James Curtis . But one man was lost to heatstroke on the way out so the column turned around and went back . A little later , in August , Ambrosio Armijo of New Mexico , with 9 , 000 heads of sheep , was approaching the fort . He sent a message to Heintzelman stating that the natives had been harassing his train since he passed the Pima Villages and many heads of his livestock had been taken by the Pima s and Maricopas . The Yumans , were now threatening the train so immediately upon receiving the message , Heintzelman dispatched fourteen men under Lieutenant Sweeny for protection . Almost as soon as Sweeny crossed the Colorado , he sent a message back stating that he expected to be attacked by some 800 warriors and that one of Armijo ' s sheep herders had been killed . Heintzelman quickly moved his entire command across the river , fully expecting a major battle . According to reports , Apaches , Mohaves and Maricopas made up part of the 800 man force . It was almost dark when the garrison left the fort . Heintzelman marched along the southern bank of the Gila all through the night and into the following morning without realizing he had passed Armijo ' s camp . When the captain concluded that he was going the wrong way , he sent a squad back down the Gila but before they had gone a mile , they encountered 100 to 150 mounted Yuman and Cocopah warriors . The squad returned to Heintzelmen ' s column which was solely infantry so the captain attempted to outmaneuver the natives . He divided his force into two and sent one to flank the group of warriors . However , as soon as the flanking party started to move , the Yumans and Cocopahs opened fire with a volley of rifle fire and a hail of arrows . Flanking the natives failed so Heintzelman ordered a charge with all of his men but before the Americans could get to close range , the natives scattered into the surrounding hills . Two Americans were wounded along with at least two natives . Colorado Expedition . With the Yumans and the Cocopah in retreat , the garrison returned to the fort . While on the way , one of the Mexicans and a Yuman rode in and told Heintzelman that the Yuma wanted to negotiate a truce . The Yuman in the party was Chief Jose Maria , lower in rank than that of Cavallo y Pelo and Santiago . Jose Maria was happy to meet with the captain and he wanted to propose a truce so they could gather their harvest . After , the Yuman chiefs would travel to the fort and sign a peace treaty . The two agreed that Jose Maria should return to his territory and discuss the matter with the other chiefs . Unsuccessful , Maria went to Fort Yuma the following day and told the Americans that he was not responsible for the war and that it was Chief Vicente who was leading the Yumans and Cocopahs during the battle along the Gila . Heintzelman issued an ultimatum to Maria , if all of the Yuman and Cocopah chiefs did not come to the fort to conclude peace within ten days , the American army would be forced to retake the offensive . Ten days passed without the appearance of any natives , and in response the garrison prepared for another expedition . Twenty men under Captain George Andrews were sent up the Colorado in one of the flatboats while Heintzelman prepared eighty men with Chief Tomas Chiuj of San Ysabel and a native guide for his journey . But just as the garrison was leaving the fort , a few Yuman warriors approached and told the captain that the chiefs would arrive within a few days . Despite this , Heintzelman did not disband the expedition , instead he advanced north along the Colorado for sixty miles when he learned on September 29 that a Yuman rancheria was eight miles distant . As usual the Yumans were warned beforehand so when the Americans captured the settlement , its inhabitants had already fled . A larger Yuman village was said to be further up the river so the column pressed on and captured it too without resistance . Captain Heintzelman later wrote that he could have destroyed much of the Yuman ' s civil infrastructure during the expedition but he did not due to the nature of his mission which was to establish a peace . He also noted that had he destroyed the villages , it would have been an attack on Yumans who were the " least guilt " as opposed to the followers of Pelo and Santiango who were on the war path . The Americans sighted many natives but they always fled , Heintzelman chased after the fleeing Yumans several times with the intention of speaking with them but they always eluded him . One night Chief Tomas Chiuj and the guide came into Heintzelman ' s camp where they told him that they had discovered the location of some prominent Yuman chiefs several days journey up the river . With only twelve days of rations from the beginning , Heintzelman could not pursue any further without supplies from Captain Andrews , the Yumans were also retreating faster than the column could advance . The same night , a few arrows were released into the camp and the Yumans set fire to some grass , this was the closest the expedition came to fighting a battle . After meeting with Andrews the column was resupplied and continued their march north along the eastern bank of the river in what was then Utah Territory . Before breaking camp , a lone Yuman warrior came in . It was Chief Huttami , the supreme leader of the Yuman people and he wanted peace with the United States . On October 2 , four more Yuman chiefs came into Heintzelman ' s camp and surrendered . Heintzelman then demanded that Cavallo y Pelo and Santiago surrender but they were among their followers , retreating to stay away from the army . The captain knew well that he had no chance of catching up with the hostile Yumans so he ordered a march back to the fort . Fort Yuma fire and the Yuma Treaty . That month a fire started at the fort because of the cook who left the door to his oven open . Wind blew some embers into the walls which turned to flames and engulfed the structure in fire , quickly it spread throughout the post ' s makeshift buildings . Fearing an explosion due to the large amount of munitions , the garrison fled to the far side of the parade ground . Captain Davidson , who was described as a coward by Heintzelman on many occasions , went after his personal belongings instead of the ammunition and food which was being salvaged by the some of the others . Davidson then fled to the other side of a nearby hill , to prevent being hit by shrapnel from a potential explosion . In November a major earthquake shook up the area , even altering the course of the Colorado . After the fire , the garrison began constructing rock and adobe walls but all were destroyed by the quake and it was not until the following year that measures were again taken to create a permanent base . For the next several months after the surrender of the Yuma , till the spring of 1853 , Heintzelman and various war chiefs negotiated until finally signing a treaty . The war between the Yumans and the United States ended but the final campaign of the conflict was about to be fought . Conflict with the Cocopah . As result of the peace , the Cocopah cut their alliance with the Yuma and conflict broke out in May 1853 . First the Cocopahs besieged three Yuman villages , killing Chief Macedon , four other warriors and ten women and children . Twelve prisoners were taken and a herd of Yuman horses captured . Cocopahs then massacred Chief Jose Maria ' s camp , killing three men and twenty - three women and children . Heintzelman noted that this massacre was an " unprovoked aggression on part of the Cocopah " . A burial detail was formed and sent to the scene of the attack , within Mexican territory and present day Arizona . The bodies were burned according to native American tradition and then the detail returned to the fort . Days later , Chief Maria arrived at Fort Yuma and informed Heintzelman that the high Cocopah chief had released some Yuman women and children but the majority were still in captivity . Maria also told the captain that the Cocopah were retreating into the mountains and that the Yuma were preparing their own raid in retaliation . The Cocopah also formed an alliance with the Paipai and Halyikwamai and together they outnumbered the Yuman warriors who gathered at Fort Yuma , which was now a center of trade with the Americans . So many warriors at the post alarmed the garrison but the Yumans were not hostile . When about 250 men were assembled , they raided south into Cocopah territory and killed seven warriors and four woman . Simultaneously , the Mohave under Chief Arateve raided Cocopah territory after the Yuma asked them to join in the war . The Mohave , by all accounts , did not want to fight , but because their Yuman friends feared for their safety , the Mohave came to their aid . In the raid , three Cocopah men were killed and two women were taken captive . According to the Mohave , years later , the Cocopah women were captured to be married to Mohave men and by producing a half Cocopah and half Mohave offspring , they would help ensure peace between the two tribes . When conflict with the Cocopah ceased the Americans at Fort Yuma received a new objective which was to prevent further bloodshed between the native tribes . Chief Arateve went to Fort Yuma where he asked the Americans to deliver a sort of contract to the four other Mohave war chiefs . The four braves were Kapetame , Asikahota , Tapaikuneche and Hatsurama , and with Arateve they were known as the " Five Brave Men " . All ranked equally and all received five letters from the American army , which , if accepted , they would no longer attack other native tibes or American settlers and they would not prevent the army from building forts and roads on their land . If the stipulations were not met the United States would go to war against the Mohave . With some convincing from Aratave , the four other chiefs eventually agreed to be peaceful and the Yuma War came to an end . Aftermath . Following the Gadsden Purchase in June 1853 , the eastern side of the Colorado became part of the United States and though the war was over between the Yuma and the Americans , the United States Army could now launch major military campaigns across the river without having to concern themselves with the Mexican military . War between the United States and the Mohave became a reality in 1858 when warriors attacked American settlers at Beale ' s Crossing in Arizona . The attack resulted in the establishment of Fort Mohave and the war ended in 1859 after the Mohave were defeated twice in two significant engagements . Later the Yumans came into conflict with the Maricopas , and in 1857 the last major battle involving the Yuma was fought . In an engagement at Pima Butte in the Sierra Estrella Mountains , the Maricopas and Pimas defeated and killed well over 100 Yumans and their allies . After which the Yuma were no longer a military power .