The Sierra del Divisor region in the Peruvian Amazon was identified as a biodiversity conservation priority back in the early 1990s. More than 20 years later and Peruvians are still waiting - some more desperately than others given all the narco-traffickers, illegal loggers and gold-miners in or near the region.

What’s so special about the Sierra del Divisor? It’s the “only mountainous region” anywhere in the lowland rainforest, according to Peruvian NGO Instituto del Bien Comun (IBC), while The Field Museum, in the US, describes it as “a mountain range” rising up “dramatically from the lowlands of central Amazonian Peru” and boasting “rare and diverse geological formations that occur nowhere else in Amazonia.” Its most iconic topographical feature is “El Cono”, an extraordinary peak visible from the Andes on a clear day.

Sierra del Divisor is home to numerous river headwaters feeding into key Amazon tributaries, eco-systems, and a tremendous range of flora and fauna, some of which are endemic, some endangered or threatened - and some with the most wonderful names. Giant armadillos, jaguars, cougars, Acre antshrikes, curl-crested aracaris, blue-throated piping guans and various kinds of monkeys, including the bald - but very red-faced - uakari, all populate the region. Effectively, it forms part of a vast “ecological corridor” running all the way from the Madidi National Park in Bolivia in a north-westerly direction along much of the Peru-Brazil border.

21 indigenous communities and 42 other settlements would benefit from the Sierra del Divisor being properly protected, states the Environment Ministry, while ultimately over 230,000 people in Peru depend on the region for food and water, according to the IBC. In addition, in the absolute remotest parts, it is home to various groups of indigenous peoples living in what Peruvian law calls “isolation.”

In 2006 Peru’s government established a 1.4 million hectare temporary “protected natural area” in this region called the Sierra del Divisor Reserved Zone. Six years later a government commission agreed it would be converted into a national park, and, all that remains now, after a painful administrative process, several key advances made this year and indigenous leaders lobbying various ministries, is for Peru’s Cabinet to approve it and the president, Ollanta Humala, to sign off on it. That is how it has stood since early May - and still nothing.

“Nine years have passed while Sierra del Divisor has waited to officially become a national park,” indigenous organisation AIDESEP stated in June. “Once again the government shows signs of having its own particular interests that could cost a lot more than it would otherwise gain, and generate more social conflict.”

“It was indicated on 7 May to the indigenous leaders involved that the issue should be discussed by the Cabinet in the next few weeks, but it still hasn’t been put on the agenda,” Lelis Rivera, from Peruvian NGO CEDIA, told the Guardian. “It was hoped it would be discussed in detail on 22 July, given that in the previous session a photo was taken of Minister [of Environment Manuel] Pulgar-Vidal showing a map featuring the Sierra del Divisor. Unofficially, it transpires that the issue was discussed at the close of the meeting, but we don’t know the details. We’ve written to Vice-Minister [of Strategic Development for Natural Resources, within the Environment Ministry] Quijandria but we still don’t have a reply.”

“[The proposed park] was discussed during the meeting,” says Rivera’s CEDIA colleague Candy Vilela, “but apparently not enough space was given to it because they haven’t come to a conclusion.”

“The government is taking so long,” Melissa Medina, from the IBC, told the Guardian. “The Environment Vice-Ministry has been written to asking why there is a delay. We’re waiting for a response.”

Why such a delay indeed, this year or in the past? Might it have something to do with the infrastructure integration plans for the region, such as the proposed - and effectively already underway - road between Pucallpa, the Peruvian Amazon’s current boom city, and Cruzeiro do Sul across the border in Brazil? Or the proposed railway between the same two cities ultimately connecting to Peru’s northern Pacific coast, declared in the “national interest” some years ago? Or the proposed railway running all the way across South America from Peru’s Pacific coast to Brazil’s Atlantic coast, a long-mooted project which has received so much media coverage recently because of Chinese interest in financing it and the visit by China’s premier, Li Keqiang, to Brazil and Peru in May?

Medina plays down the role of the latter in explaining the delay, saying the proposed route is just to the south of the Sierra del Divisor. “What we do know is that it’s not because of the Chinese train,” she says. “We know that Chinese workers have done an overflight of the area and have said that the route it will follow will not cross the Sierra del Divisor.”

CEDIA’s Rivera says that no railway route has officially been proposed yet by the Transport Ministry “so we can’t know if it would cross the proposed park or not”, but points out that, according to the Chinese officials involved, it looks like the Sierra del Divisor would be spared.

“A mission of Chinese and Peruvian functionaries from the Transport Ministry, together with the head of the Sierra del Divisor Reserved Zone, did an overflight [of the proposed route] in the second week of July between Pucallpa and the Brazil border, passing to the Sierra del Divisor’s south,” Rivera says. “The Chinese said they wouldn’t touch Sierra del Divisor and didn’t want to do overflights of alternative routes.”

Or might the delay be explained by oil and gas industry interests? Perupetro, the state company promoting oil and gas operations, tried to open up what would be the entire southern part of the park for exploration before backtracking in 2008, while the London Stock Exchange-Alternative Investment Market-listed company Maple Energy has been pumping oil for years in a concession just overlapping the west of the proposed park. More significantly, Canadian-headquartered company Pacific Rubiales Energy runs a one million hectare oil concession that would overlap the entire northern part of the park if it was established, and conducted its first phase of exploratory drilling and seismic tests in late 2012 and 2013 in what would be the park’s far north. Clearly, it wouldn’t be good PR for either Pacific or Peru to explore for oil in, or exploit oil from, a national park, although it wouldn’t be the first time a concession and park have overlapped. Indeed, according to the IBC, it has been agreed that Pacific’s “rights” to operate will be respected if the park is created.

Medina plays down Pacific’s interests in explaining the delay too. “Neither is it because of their oil concession,” she says. “Although it overlaps the area, the company’s activities will be outside it.”

Rivera agrees. “Apparently there is no problem since it has been determined that previously acquired rights should be respected,” he says. “Furthermore, Pacific is pursuing seismic exploration activities outside the proposed park, which leads to us to think they won’t intervene, while Maple’s concession overlaps a very small part of it.”

Others believe oil and gas interests have played a key role in the delay. According to lawyer Cesar Ipenza, the administrative process to establish the park has been made “almost impossible” by the Energy Ministry and Perupetro, although he says weak government capacity is partly to blame too.

“In addition to the [administrative] blocks by the Energy Ministry and Perupetro, it’s been the inability of the environment sector to put the issue on the Cabinet’s agenda,” Ipenza told the Guardian.

Oil sector opposition is also acknowledged by Maria Elena Diaz, the head of the Sierra del Divisor Reserved Zone, who works for the Environment Ministry agency administering it. She told the Guardian in May she was “very happy” about the progress being made towards establishing the park, but both Perupetro and the Energy Ministry were against it.

Rivera also dismisses the idea that potential agricultural interests could be blocking the park, given that it is a “mountain area” with “less than 3%” agricultural potential. “No other reasons for the delay remain,” he says. “The only thing could be that someone in the Executive is interested in seeing the logging, illegal mining, coca cultivation and narco-trafficking in the region continuing to prosper.”

If established, the Sierra del Divisor National Park would stretch across two of Peru’s biggest regions, Loreto and Ucayali, and run adjacent to the international border where, right the other side, Brazil created its own Sierra do Divisor National Park years ago. Will Peru follow suit? The region certainly needs protecting - as urgently as possible. Reports of illegal invasions have been made for years, and US-based NGO Amazon Conservation Association recently released satellite images showing ongoing deforestation for coca cultivation, illegal logging and gold-mining in the proposed park, and new logging roads heading towards it.

Arguably, some of those most at risk are the indigenous peoples in “isolation”, who lack immunological defences to common infectious diseases and could be decimated by contact. The park would overlap one reserve established in the 1990s for the Isconahua, or “Iscobakebo”, in “isolation”, as well as another two proposed reserves for other groups - none of which have been protected by the government. Lawyer Ipenza describes the Culture Ministry’s failure to take action against logging and other “serious problems in the Isconahua Reserve” as “almost incredible.”

The Culture and Environment Ministries could not be reached for comment.