A land and air search is underway on Fraser Island for a woman who went missing during a hiking trip on the World Heritage site.
It is understood the 73-year-old was with her husband and two friends on an organised hiking tour when she became separated from the group on the Valley of the Giants trail on Thursday.
Maryborough Patrol Group Inspector Brooke Flood said the experienced hikers were walking at different paces through the bush when they realised the woman was lost.
"After they got to the end of the trail they realised that she hasn't arrived," Inspector Flood said.
"They went back to retrace their steps and weren't able to find her."
Police launched a search with the assistance of the rescue helicopter about 7:00pm, but failed to find the woman.
Two helicopters resumed the search on Friday morning with the assistanced of general duties police officers, water police and Parks and Wildlife officers.
The woman is carrying a mobile phone, but reception is poor on parts of the island.
Police said she had sufficient clothing and food, had previous trail walking experience and had no prior medical history.
"The missing person actually has her mobile phone and sent an SMS message about 7:30pm stating that she was lost," Inspector Flood said.
"She is of good health and she is an experienced hiker so we don't have any medical concerns at this stage."
Jane Needham, who owns another hiking tour business on Fraser Island, said she was shocked to hear someone lost on a guided tour.
But she said the trails had become very overgrown during the COVID-19 pandemic.
"The Valley of the Giants is an area that is very heavily forested and the hiking trails in that area haven't been maintained," she said.
"The trails aren't in good condition … there's a lot of trees down."
'Servicing has been a priority'
In a statement, the Department of Environment and Science (DES) said the COVID-19 closure had no impact on the numbers of Queensland Parks and Wildlife Service (QPWS) rangers on Fraser Island.
"During the closure, rangers conducted a number of prioritised maintenance works," DES said.
"Following the lifting of closures, and with the influx of visitors, amenities servicing has been a priority in accordance with the COVID-safe plan, as well as ongoing road maintenance and education and compliance efforts to ensure park visitor safety."
DES said the Valley of the Giants trail, as part of the Great Walk, received routine maintenance and featured directional signs.
