A sacred Indigenous site on a Queensland mountain has reopened following an incident of vandalism where an important rock surface was marked with a religious message.

The vandalism, reading "Jesus Saves Just Ask Him", was etched using a power tool at the base of Mt Beerwah on the Sunshine Coast in May.

The affected mountain holds immense cultural value for the local Jinibara community and is situated within the Glass House Mountains National Park.

Recognising the significance of the site, it was temporarily closed to allow rangers and traditional custodians the opportunity to mitigate the harm caused.

The anticipated reopening date for visitors is scheduled for Friday, as confirmed by the Queensland Department of Environment on Thursday.

Efforts to restore the site have encountered challenges due to subsequent meddling by a member of the public, as conveyed in an official statement by the department.

"Queensland Parks and Wildlife Service are appealing to the public not to interfere with the site and to allow QPWS, the Jinibara and specialist conservators (to) conduct the remediation works."

Offenders could face fines of up to $500,000 and two years in jail.

It's also an offence under the Aboriginal Cultural Heritage Act 2003, with penalties of up to $143,750 for individuals.

When the vandalism was first discovered, QPWS regional director Geoff Brittingham said it had left rangers and the Jinibara people "reeling with disgust and sadness".

"Not only has this callous person or persons extensively defaced an area of rock, but they have also caused immeasurable damage and hurt to the Jinibara's well-being," he said.

Senior Ranger Nat Smith said "the person or persons responsible could be liable for the cost of rehabilitating the site, which may cost tens of thousands of dollars."

"Anyone who defaces our national parks will be fined because rangers investigate every incidence of environmental vandalism," she said.