The Kimberley's tourism industry has expressed concerns regarding the apparent "secrecy" of allegedly unannounced mining operations near the popular Horizontal Falls visitor spot.
On Monday, a local operator was out in a tourist plane visiting the famous attraction when they spotted a bulldozer pushing a road into bushland, around 15km south of the Falls.
The operator also noticed a Rio Tinto exploration camp was under construction, and inquiries later confirmed the camp was to be a base for a proposed copper exploration operation.
Environs Kimberley executive director Martin Pritchard said activists "reacted with disbelief" when they received footage of the bulldozer, and said the conservation group would now be seeking a meeting with Rio Tinto to find out more about the operation.
"Last week we were sent photos of a bulldozer pushing a road into the wilderness 15km south of the Falls and the setting up of an exploration camp by Rio who are apparently exploring for copper," he said.
"We're shocked that Rio would even think of mining such a sensitive place. Former company chief Sam Walsh stood with West Australian Premier Colin Barnett just two years ago and said that the Mitchell Plateau was too sensitive to mine. Rio's new management obviously doesn't understand the sensitivities of the Horizontal Falls area, otherwise they wouldn't be exploring there."
Mr Pritchard said he had been approached by concerned tourism operators, who had expressed concerns a copper or nickel mine "could cripple the industry".
"The Horizontal Falls experience brings in tens of millions of dollars to the Broome nature tourism economy and a copper mine is a real threat to the Kimberley tourism brand," he said.
"The Barnett Government put a no-mining zone around the Horizontal Falls in 2012, and Rio's new exploration push is just 10km outside that zone.
"The McGowan Government needs to make a serious policy decision to ensure this part of the Kimberley coast is protected from industrialisation or we'll see mines popping up everywhere, and the whole tourism experience will be gone. All they need to do is expand the current mining exemption area."
Local tourism operators maintain they were not properly informed about the company's intentions to begin exploration in the area, and Australia's North West Tourism chief executive officer Glen Chidlow said it was important Rio Tinto communicate with the local community as a potential exploration site could affect the area's appeal.
"The Kimberley tourism industry would be very concerned with any proposed mining or exploration within close proximity of the Horizontal Falls," Mr Chidlow said.
"Talbot Bay on the Kimberley coast is the only place in the world where this natural phenomenon exists, and it is a standout attraction for visitors to the region.
"Cruise ship, helicopter and fixed wing operators all provide an outstanding experience for visitors, many of whom are coming to the Kimberley specifically to see this attraction.
"Apart from the Falls themselves, the appeal of visiting this part of the Kimberley is its pristine wilderness and remoteness – an image that just doesn't fit with a nearby mine site.
"The tourism industry would no doubt be opposed to activity that impinged on this particular attraction, which is unique in every sense of the word."
When asked if tourism operators and other members of the community had been advised exploration was underway, Rio Tinto said:
"Our exploration area is about 20km from the coastline and does not include any river that acts as part of the catchment area for Horizontal Falls."
The company confirmed they were exploring in the area for a possible nickel or copper mine in the future, and they were operating outside the boundaries of the mining exemption region – on land owned by the Commonwealth Government's Australian Defence Force.
"Our exploration area is about 20km from the coastline, where the Horizontal Falls is located," a spokeswoman said.
"Rio Tinto Exploration is looking for Nickel and Copper at Yampi in the Kimberley, Western Australia.
"Exploration activity, even if it finds something that could become a mine one day, is the start of a very long process of evaluation and commercialisation that typically takes around a decade to progress."
Rio Tinto Exploration was given the green light in 2016, when the company signed a Deed of Access with the Federal Government in November – the same month parts of the Falls was granted mining exemption for a further two years.
The company flagged its intentions to explore two tenements in the Yampi Sound Training Area.
One month later, Rio Tinto Exploration signed an agreement with the Dambimangari Aboriginal Corporation relating to the same two tenements and completed a heritage survey.
Mining in the region was banned in 2012 when the former WA government established a 72 square kilometre mining exemption area surrounding the Horizontal Falls.
The former state government established a 160 square kilometre national park and a 3000 sq/km marine park in the region in 2013, and awarded the area a Class A status in order protect it from further development.
The status prevented current and future mining activity in the area, and provided greater protection for the tourist attraction than national park status. When the status was first established, then-Resources Minister Norman Moore said the mining ban would be up for review every two years.
In May 2014, the Mining Act (1978) was amended. Section 19 was developed, which created an "exemption clause".
Under the exemption, no mining tenure can be applied in the Horizontal Falls region unless expressly stated by a government minister.
Former Environment Minister Albert Jacobs had the opportunity to review the Horizontal Falls land protected under the section 19 tenure in November 2016, and extended its protection through until November 2018.
Department of Mines, Industry Regulation and Safety environment executive director Karen Caple said due to this exemption, there "are [currently] no mining leases within the proposed Horizontal Falls National Park".
"However, some 15km south of the [section 19] exemption area, an approved exploration activity is being undertaken, involving track clearing, camp site and geophysical evaluation," she said.
"This approval includes a number of environmental management and rehabilitation commitments."
Ms Caple said she was confident both tourism and resource exploration could co-exist in the area.