The rural nurse clinic answerphone for the area gave an emergency cellphone number to talk to a nurse, "but sadly the clinic does not receive any reception".
Mrs Adamson said Hari Hari had a sizable hotel-motel which accommodated many tourists who could not use their phones unless they walked down to the cemetery.
She had spoken to Spark "many times" which could give no undertaking to improve reception.
Health agencies often reminded people of appointments via cell phone, unaware of the lack of reception, she said.
"My specialist in Christchurch still rings on the cellphone which means I have to go down the road to get the message. In my mind, totally unacceptable especially when it is wet."
Another Hari Hari resident, Karen Mathieson, said she now forgot to keep her phone charged given it was mostly unusable, after moving to the area four years ago
Vodafone reception was just present at the northern end of the town -- on the hotel's window sill -- but there was none from Spark. "If we can get full coverage that would be awesome," Mrs Mathieson said.
Wanganui Flat resident Mary Molloy, without cellphone reception, confirmed the Hari Hari residents group had been advocating for better cover.
She suggested the West Coast District Health Board had a role in the lobbying given its reliance on effective communication to serve the region.
Spark media spokeswoman Vicky Gray said Spark would "love to cover everyone" but New Zealand's challenging topography and low population density made this "simply impossible".
Access to infrastructure, topography, accessibility and the number of customers were all factors.
"Unfortunately we don't currently have plans to extend our mobile coverage in the Hari Hari or the Haast areas."
The Spark mobile tower at Mount Hercules, to the north of Hari Hari covered some customers. Improvements in August had provided "some limited improvement", with the company noting an increase in local use at the site in the past month. Spark had invested $1 million in co-locating on a number of the Government's Rural Broadband Initiative sites on the Coast, in the past two years.
Vodafone said it was committed to connecting more New Zealanders than ever before.
- Greymouth Star