Brazilian journalist Euclides da Cunha referred to Scharff as the "great land lord" of the Upper Purus, where many rubber exporters were dependent on him by 1905.

The Geographic Society of Lima credits Scharff with the establishment of a portage route around 1905, that connected the Upper Purus to the Madre de Dios River.

[13] Some of these populations include various Yine, Matsigenka, Cushitineri, Etene, Kudpaneri, Nachineri, Amahuaca, Ronohuo, Yaminahua,[13] Asháninka, Conibo, Huitoto,[14] and Mashco-Piro peoples.

[17][14] According to Sociedad Geográfica de Lima, Scharff controlled such a large portion of the Upper Purus basin that it would take twenty days of travel by canoe through portage routes to get from his post in Hosanna to his station at Alerta.

[17][14] In a 2006 article titled "'Purús Song': Nationalization and Tribalization in Southwestern Amazonia", Gow refuted the claims that the Isthmus of Fitzcarrald, as well as the portage route between the Sepahua and Cujar tributaries, were discovered in the 19th century.

[32] According to Susanna B. Hecht, Scharff extensively implemented a "tribute model" across his estate and appeared to depend on discipline maintained by powerful chiefs in order to keep his workforce compliant.

Hecht also noted that "Scharff used the Peruvian military based in Iquitos to mediate his local quarrels, rather than the bands of thugs that more powerful river masters typically commanded.

"[21] The organization between Delfin, Collazos and Scharff initiated a series of migrations beginning in 1899 with the intention of establishing new rubber stations along the Purus River.

[23] According to Gow, "many Piro people moved from the Urubamba to the Purús [and Yurua] as debt slaves of rubber bosses like Scharff who were seeking to exploit the rich stands of the rubber-producing caucho of the latter river.

"[36] Hecht writes that the decision to relocate was also partially influenced from the pressure induced by slave raids in the region, perpetrated by other Peruvian caucheros like Julio César Arana.

[40] Years later, a newspaper from Manaus named O Paiz published an article containing a report from Brazilian colonel José Ferreira de Araújo, which stated Scharff and his caucheros were responsible for killing "thousands of indigenous people" along the Jaminauá and Paranã do Ouro tributaries of the Upper Envira River.

[42][49][j] When the Piro natives inquired about who had initially started the fighting on the Purus River, the answer was disputed between "Scharff or Cardoso da Rosa to 'the Peruvians' or 'the Brazilians'".

[52] The Amahuaca retaliated against these incursions and occasionally attacked the cauchero camps, where "they killed their white patrons, their families and their indigenous peons, and took away their firearms and any other manufactured object that was within their reach.

[63] After requesting help from Iquitos,[64] a detachment of twenty soldiers and two Peruvian sergeants arrived on 23 June 1903, to the Scharff territory on the Chandless River.

He makes appearances as a backwoodsman in the remoter tributaries of the Upper Amazon, but he seems in many ways to have been an agent provocateur mobilized to bring attention to Peruvian presence in the region, to manufacture conflict, and to draw in the military from Iquitos into the Purus.

[72] The Asháninka chief Venancio Amaringo had migrated from the Ucayali basin to the Upper Peru's region sometime around 1904,[83] and Da Cunha mentioned that he was operating a large plantation[77] named Tingoleales, which produced bananas and cotton.

[85] Leopoldo Bernucci states that "since Da Cunha's efforts to categorize him [Scharff] in a social taxonomy were in vain, once again Euclides resorted to science", producing an archetype that describes the rubber baron in his essay.

[54][53][87][u] Curanja, which was once a prosperous and lively station, today it is in clear decay and lifeless, for the which contributes greatly to the removal of caucheiros, currently dedicated to the extraction of rubber.

[92][v] Scharff settled his barraccas on the Ceticayo, Chanchamayo, Lidia, Curiacu, Pariamanu, Esperanza and Huáscar tributaries of the Las Piedras River according to Wenceslao Fernández Moro, a Dominican priest who lived in the Madre de Dios region.

[92] Scharff managed to rebuild his fortune in a short amount of time after the border conflict with Brazil according to his biographer at the Geographic Society of Lima.

[97] The development of a new portage route from a tributary of the Las Piedras River that would allow access into the Urubamba began around 1909, however Scharff did not live long enough to see its completion.

[13][aa] Around 1908, anthropologist William Curtis Farabee was travelling through the region to find "the home of the Amahuaca" which was located around the Sepahua, Piedras, and Purus Rivers.

[100]When the reports about the attack against Scharff's settlement reached his other workers, Baldimero Rodriguez along with a group of other men went to investigate what had happened, and to find out if there was any rubber abandoned there.

[97][ad] The Sociedad Geografica de Lima's account stated that the rebels attacked Scharff's settlement on the Curiyacu tributary during the afternoon of 28 July 1909.

[112] The wife and son were able to travel to Puerto Maldonado, where a number of Scharff's employees were gathering in hopes of avenging their boss,[113] and collecting any remaining rubber at his station.

[98] Sometime after the 1909 mutiny, the Brazilian federal government denied a reimbursement claim of Scharff's, regarding an estimated £200,000 worth of damages suffered during the conflict on the border.

[80] An application that was filed by Carlos Scharff for a "vast concession" of land in the rubber forest along the Upper Las Piedras River, was also declined by the Peruvian government.

His mother found an ally and a protector by the name of Teobaldo Gonzalez, who helped sponsor the young Scharff, and had been apparently "treating him as a true son.

[114] In early June 1940, during a flight over the Manu River, pilots Luis Conterno and Votto Elmore spotted a settlement near the beginning of the Pinquen tributary.

His grandfather and father, together with the priest, had raped all of the young indigenous women in the area, he told me proudly - "hundreds of them, just like this one here", he added pointing to the plump Asháninka girl sitting in the back end of the boat ... Whilst we were eating and drinking, Don C.D.