"It was out on a bluff. It looked isolated, and I didn't have a good feeling about it."
When she went over and looked, she discovered the words written on the stone were Maori.
"I recognised the Maori language because my father was originally from New Zealand and had been great friends with James K Baxter for years. So there was plenty about Maori in my childhood."
Ms Heald said she had copied everything off the stone into her journal.
"The rest, as they say, is now history," she said.
Her late father Chris Heald was involved in Australian politics and, at the time, worked for the Federal Minister of Justice in Tasmania as an adviser.
He put wheels in motion to have the body exhumed because Hohepa was a Whanganui River Maori.
In 1988, Mr Heald had written Hohepa's story, The Lost Son of Wanganui published in the New Zealand Listener.
"You see, Hohepa had been sent to Tasmania as a Maori convict. They had tried to make an example of him, but no other convict had ever had a grave, so there was something different about Hohepa."
He was a member of Ngati Hau of Te Ati Haunui-a-Paparangi, born in the early 1820s.
When Te Rangihaeata of Ngati Toa started the armed resistance to the settlers in the Wellington area in 1846, Hohepa had joined other Wanganui Maori and travelled to Te Rangihaeata's pa at Taupo, Porirua.
Hohepa fell victim to Governor George Grey's laws and was captured near the Pauatahanui Hills, Porirua, together with six other Wanganui Maori.
They were all convicted of rebellion against the Queen and were sentenced to be "transported as felons for the term of their natural lives" and sent to a Hobart Town, Van Diemen's Land (Tasmania) to a penal colony.
From Ms Heald's discovery of the grave in 1985 it took three years of negotiations between the New Zealand and Australian governments. Six elders of Hohepa's tribe on the Whanganui River travelled to Tasmania to bring him home.
Hohepa was reburied on August 8, 1988, at Roma cemetery, Jerusalem, on the Whanganui River.
Ms Heald said seeing a special preview of the opera last week and coming to Wanganui and through to Jerusalem had been a very special journey.
"The opera was just amazing ... so many spine-chilling moments, and going up to Jerusalem - well, I just fell in love. What a beautiful, beautiful place."