The indigenous Munduruku group has some 14,000 people and concentrates in the region of the Tapajós basin in the Brazilian state of Pará, either in the Munduruku Indigenous Territory (which comprises 23,820 square kilometers) or in nearby towns and territories. Situated along the Tapajós river and tributaries such as Cururú, Teles Peles and Das Tropas, the communities in the territory live from fishing and hunting, fruits and açaí. The river is the main source of drinking water and also culturally and spiritually important. This very remote area of the Amazon also borders the conservation unit of the Crepori National Forest (Flona Crepori) and is close to a series of mega dam projects, some of which have already been realized and provoked indigenous resistance (as e.g. the Munduruku and other groups occupied the Belo Monte and the São Manoel dams). Before the arrivals of colonialists, the Munduruku used to occupy vast areas of the Amazon and practiced a warlike culture. Today they are still known for their brave resistance, led by the “Ipereg Ayu Movement” (“people who know how to defend themselves”), but also for a very horizontal consensus-based organization and particularly strong participation of its female members who participate in mobilizations and direct actions of the Ipereg Ayu and organize in the Wakoborun association. 
Illegal mining has become the major issue for the communities, which however have been practicing artisanal mining since the 18th century. Officially all mining operations in indigenous territories are prohibited by the 1988 Constitution and article 169 of the ILO Convention. However, Brazilian’s Vale and some Canadian mining companies are eager to move in and are just waiting for the Congress to change the mining code and regularize mining in indigenous territories, a legislative initiative that has been discussed for a long time but was recently pushed forward by the increasingly influential mining lobby. Mining is only authorized in the nearby Garimpeiro Reserve of Tapajós, created by the miner-friendly military government in the 1980s. There, an estimated 50,000 garimpeiros operate today, but mostly still without license, and as the area is poorly demarcated and monitored, they have advanced to the Flona Crepori, which was created in 2006 but has never been effectively monitored. While first garimpeiros (Brazil’s illegal miners) arrived in the area in the 1960s, numbers dramatically augmented in the 1980s after the Tapajós river was reported as one of the world’s richest gold reserves, but Munduruku defended their territory and after a long community struggle eventually achieved demarcation. After that, also some Munduruku individuals have opened small-scale mines as way to generate cash income to deal with increasing contact with non-Indians, but they usually operate with lighter equipment to limit environmental harm. More recently, however, mining invasions into Munduruku territories have augmented and in 2010, the so far largest number of garimpeiros entered about 21 villages, despite protests by the Ipereg Ayu movement in name of most of the Munduruku. Since then, mining is no more small-scale, artisanal but rather resorts on a well-organized infrastructure and network and the use of heavy machinery. A village called PV (for Posto de Vigilância, watch post), situated close to the headwaters of the Das Tropas river, has became the main hub for the illegal mining network, although it was originally created for territorial vigilance (but never received personnel from FUNAI). A chief miner reports that after failed previous attempts to settle in the area, they have negotiated a deal with some local leaders. Today, miners live next to about 15 remaining Munduruku families, a public school room was converted into a dormitory and also food and liquor stores and a brothel have opened up. A road network spreads out to the mines in the surroundings. An unauthorized airstrip was installed where about 10 small planes arrive daily to bring food, drugs and mechanical parts and transport merchants and sex workers. 
Illegal mining in the area has caused severe impacts on the Munduruku community and their environment. Some note that mining itself is not the problem but the way how it is done - contrary to artisanal miners, the new garimpeiros do not live with and from nature but rather receive supply from outside, leading to the careless destruction and pollution of vast parts of the area. Most notably, river pollution through mud, runoff sediments and toxic mercury (which is used to purify gold) has become severe. Many families report that the water has became undrinkable, that bathing causes rashes and that they were not able to fish for years, leaving children hungry; also forests and in particular açai palms and planted timbó - a culturally important ceremonial plant – are being destroyed and wild animals have disappeared. Besides the devastating environmental impacts for local communities, mining is also overall a growing factor for deforestation in the Amazon, with the Tapajós basin as one of the main hotspots and the largest concentration of illegal mining in the whole Amazon.    The invasions of miners also caused transformations and divisions in the community. Villages became confronted with wage labor, industrial food, incidents of violence, alcoholism, prostitution, drugs, and illnesses such as malaria and diarrhea. As miners came with gifts and often promised to share small percentages of the earnings, some villagers were easy to coopt, also because communities lack basic support from the government (such as of transport, health and education, to which they would be legally entitled). It is reported that miners seduce young indigenous girls with cheap rum and introduced drugs to the young generation; some Munduruku have started to work in the mine as cheap labor, and a few even became bosses of others, moved to the city and started to defend mining in the territory. A leader of a Munduruku association in Jacareacanga claims that not all villages were opposed to mining as for example in one of the areas 22 out of 123 villages receive payments to compensate for the caused damage. A female Munduruku leader in turn reported that she and two other leaders faced death threats from a drunk, armed Munduruku who collaborated with the miners and that also a gold remuneration was promised to the person who assassinate her (which was also proved by a recorded phone call). Thus, miners have created and exploited divisions among the community, which now allows them to claim that they have the permission of the local leaders. At the same time, daily life and social structures have changed in many Munduruku villages and the security situation has become worrying, particularly for the resistance leaders. Also police raids, which have been infrequent, ended in violent incidents as for example in 2016, a police man was killed by a garimpeiro during an intervention. In 2012 the police arrived by surprise and after miscommunication in the Munduruku village of Teles Peles and immediately initiated fire on a gold mining barge. As villagers felt threatened the situation became out of control and police opened fire and threw bombs while some villagers defended themselves with arrows. A Munduruku man was shot dead and several others got wounded. When realizing that the raid had been filmed, the police intended to destroy the evidence and told the community to lie about the events and blame the barge owner or otherwise face persecution; they jailed some Munduruku villagers and protocoled that “over 100 armed Indians in war paint” were awaiting them in order to attack. However, four years later, video material appeared in which communities report the “day of terror” to visiting journalists, explaining that they had been communicated a meeting instead of a raid and were therefore wearing their ceremonial clothes which includes bows and arrows. The evidence led the Federal Public Ministry in 2017 to file a lawsuit against the state and demand a collective compensation of 10 million R $ for the affected community, which since the incidents has lost all trust in pubic authorities. 
As a response to these increasing threats by mining, a large part of the Munduruku group has organized and pointed to the problems and devastating impacts. A representative of a Munduruku association stated: “We live in the midst of capitalist exploitation, where everyone controls our territory except us, as if we were slaves. What we seek is autonomy."  They also criticize the lack of law enforcement and feel largely left alone by the state but increasingly threatened. They state that mining has to be stopped, otherwise the situation will get even worse, which is why they have increasingly undertaken direct action. For example, in 2014 women and men of the Ipereg Ayu Movement patrolled for over three weeks along the 226-km Das Tropas river to detect illegal mines and confiscate equipment, but also after miners returned. Even more exasperated in 2017, they decided in a general assembly to no longer accept the situation and to destroy all machinery and expel miners from their land, which led to a published manifesto in which they expressed their anger about illegal mining and the ignorance of public authorities who would just stay in their offices. In a following patrol in early 2018, a large group of Munduruku warriors armed with bows, arrows and shotguns, started to head upstream with the aim to reestablish authority in the PV village, accompanied by older community members, children and a journalist (while FUNAI’s representative refused to join due to a lack of security). They confronted miners along the river and in PV and expressed the pain and indignation of the majority of the Munduruku community, while some miners again pointed to existing agreements and started to make promises. The Ipereg Ayu still demanded them to leave and announced that on their next patrol, only warriors will come. The resistance group has started to use social networks to spread awareness and mobilize; female leaders report that the struggle against illegal mining and the hydroelectric projects has contributed to the empowerment of women in the community and that now they would start to fight for a political voice. 
The government reaction has been ambivalent, slow and largely ineffective. The Munduruku made complaints at a number of institutions, including the Federal Public Ministry, which has own indigenous litigators, the environmental and indigenous agencies IBAMA and FUNAI, and the Chico Mendes Institute for Biodiversity Conservation (ICMBio), which manages protected natural areas for the federal government and had recently even asserted that mining is under control and that there was no impact on the fishes. An IBAMA coordinator in turn acknowledged the high pressure from illegal mining on the Munduruku community and that environmental problems come along. FUNAI, which was supposed to guard the indigenous territory was significantly defunded over the last years. Law enforcement operations against illegal gold mining in the Tapajós basin have been infrequent and usually lasted only a few days, allowing miners to quickly regroup and reinstate the mines after authorities leave. In reaction to denunciations by the Munduruku since at least 2010, some raids have taken place but - as police has become more cautious after the mentioned violent incidents - largely focused on destroying mining equipment; forces arrived heavily armed but usually outnumbered. In 2017, the Federal Public Ministry urged IBAMA and ICMBio to undertake periodic enforcement operations along the Das Tropas river, but still little happened. The government authorities also appear divided; while there are still supportive national officials, many state, federal and local politicians and administrators are linked to the mine owners and the mining sector has established a powerful political lobby with own elected deputies in the congress. As local politics are often captured by mining and some towns in the region economically depend on illegal gold trade, social acceptance has risen and police raids are unpopular; thus also law enforcement authorities are often coopted by mining interests. The area, as other parts of southern Pará, has become a new lawless frontier of the Amazon in which miners as well as land-grabbers and loggers have a lot of power while the state is largely absent. 
However, after NGOs such as Amazon Watch and the Indigenous Missionary Council, also national media started to draw attention to the recent confrontations and Munduruku direct action. With the finding that miners continued to operate even after, the government seems to have become less tolerant against illegal mining of industrial scale and the federal police finally made another more coordinated raid in the Munduruku territory and the Flona Crepori in May 2018, using helicopters, planes and additional IBAMA and ICMBio personnel. They entered mining camps, issued fines of $ 13 million and destroyed equipment while at the same time raids in offices of the illegal gold mining network took place in two cities. This included the regional gold trader Ourominas in Santarem and the seizing of gold, millions of cash and computers. It was found that the company had bought gold worth $19 million between 2015 and 2017, that it ignored all tracing regulations and that all of the gold was of illegal origin in 2015. The company owner was then charged for organized crime. Since then, the security situation has become even worse and death threats against Ipereg Ayu leaders, who have become more visible, have multiplied, while miners were not removed from the territory. Munduruku became more unsatisfied about lacking protection of their leaders and the failure of the police to combat the ongoing mining, as dozens of excavators still work, miners already brought new equipment and some of the biggest mines were not disrupted by the raid. They stated that once again, public authorities did not do their job. Also garimpeiros reacted to the raid with protest against their perceived criminalization by blocking the BR-163 transamazonic highway. Shortly after, the mine operators sent delegations to Brasilia to lobby within the ruralist bloc for a new bill to stop IBAMA from destroying seized mining equipment and instead force them to return it to local authorities. With such a law, is likely that those authorities sympathetic to the miners would return the equipment to the miners.