The Australian Capital Territory's only known Aboriginal art site has officially reopened.

Sacred to Ngunnawal people, the the Yankee Hat Rock Art Site, located in the the Namadgi National Park had been closed for five years following damage from the 2020 Orroral Valley bushfires.

Its reopening comes after new bushfire resilient visitor infrastructure was installed at the site.

They include a new steel viewing platform, elevated boardwalk, interpretive signage, improvements to the three kilometre access walking track, a steel footbridge over Bogong Creek, as well as new landscaping and infrastructure at the picnic area and carpark.

ACT Minister for Heritage, Chris Steel, said the Yankee Hat Rock Art Site is an important part of ACT's Traditional Custodian's heritage.

The area features some of the earliest rock art identified in the ACT.

"The figures in the rock shelter were painted over a period of hundreds or possibly thousands of years, as evidence from the site suggest that the apical ancestors of the ACT and region were camping in the area as long as 3,700 years ago," Mr Steel said.

"This art is culturally significant and highly valued by the Traditional Custodians because of its tangible and spiritual connection with their ancestors."

Senior Ngunnawal ranger Adrian Brown said local Elders continue to inform the ACT Parks and Conservation Service on how to monitor and care for rock art at Yankee Hat.

"They often come up and help us do the monitoring," Mr Brown said.

"It's really important that we do this and that we maintain this story.

"Our stories are always going to be there for our next generation so that they can continue their culture and understand who they are as aboriginal people."

The visitor infrastructure upgrades were funded through the Australian Government's Black Summer Bushfire Recovery Grant.

ACT Minister for City and Government Services, Tara Cheyne, said she was glad to see the "this important and highly valued site" reopen to the public.

"These upgraded facilities at Yankee Hat were carefully designed to not harm or disturb the site's cultural significance or the natural surroundings," Ms Cheyne said.

"The ACT Government worked with Traditional Custodians throughout this project, as well as consultants for heritage and archaeological advice, so the area can continue to be appropriately preserved.

"I encourage the community to make the trip to Yankee Hat to visit the site but please do not touch the art or the rock surface as oils from your skin will damage the painting which is unique to the ACT and the Southern Tablelands region."

Federal Member for Bean, Daniel Smith, welcomed the reopening.

"Yankee Hat is a special place of high cultural value," Mr Smith said.

""Canberrans have been looking forward to this reopening for a long time and recognise the efforts made to protect this special place."

Visits to Namadgi National Park can be planned for using the Parks ACT website.