About 60km northwest of Tom Price, the Brockman 4 deposit envelopes the Juukan Gorge, a culturally significant site for the local Puutu Kunti Kurrama and Pinikura peoples.
Despite three separate archaeological digs at the site finding evidence of human occupation dating back 46,000 years - making the site one of the earliest occupied locations in Australia - Rio Tinto went ahead with a planned blast last week that flattened the two rock shelters.
The Puutu Kunti Kurrama Aboriginal Corporation said in a statement that archaeological research had revealed highly significant ancient artefacts in two rock shelters at the site, with some known to date back 20,000 years before the previous Ice Age.
It said its people are distressed by Rio Tinto's act.
Artefacts recovered in three short visits to the rock shelters in 2013 include charcoal, plaited human hair, grinding and pounding stones and a macropod fibula bone sharpened into a tool.
Puutu Kunti Kurrama and Pinikura Aboriginal Corporation chairman John Ashburton said it tried to get Rio Tinto to stop the blast or at least limit the damage to the rock shelters but Rio Tinto had already laid the charges and they could not be removed safely.
Ashburton said his people were frustrated by a rigid regulatory system that did not allow important new information, such as the archaeological finds in the Juukan Gorge to be considered once a Section 18 notice is granted.
A Rio Tinto spokesman told Australia's Mining Monthly the company had been working with the PKKP traditional owners in relation to the Juukan area for the past 17 years after a formal Native Title agreement was signed in 2011.
"In 2013, ministerial consent was granted to allow Rio Tinto to conduct activity at the Brockman 4 mine that would impact Juukan 1 and Juukan 2 rock shelters," he said.
"This process included archaeological and ethnographic fieldwork to identify places of significance, as well as funding an extensive salvage management program in 2014 that collected cultural materials from the rock shelters.
"Rio Tinto has worked constructively together with the PKKP people on a range of heritage matters and has, where practicable, modified its operations to avoid heritage impacts and to protect places of cultural significance to the group."
Nevertheless the incident has put a spotlight on the inadequacies of WA's Aboriginal heritage laws.
WA Aboriginal Affairs Minister Ben Wyatt told AMM approval for the site works occurred in 2013, under the previous Liberal government, and he was not aware of the blast or the Native Title holder's concerns.
Wyatt said cultural heritage legislation moving through parliament would better protect Aboriginal heritage in WA.
"The proposed new Aboriginal Heritage legislation focuses on agreement-making between traditional owners and proponents," he said.
"It will provide for agreements between traditional owners and proponents to include a process to consider new information that may come to light and allow the parties to be able to amend the agreements by mutual consent."
Wyatt said the new legislation will also provide options for appeal should either party is not compliant with the agreement.