The trail would need to be temporarily realigned to accommodate the mining operation, which would also be near the Clutha River and Teviot Rd.
Hawkeswood Mining Ltd has been asked for more information by the Central Otago District Council about its proposal, after it applied for a 20-year resource consent last month.
It will also need consent from the Otago Regional Council.
If approved, the alluvial mining operation would run for about 14 years.
Up to 20 staff would be employed on the project, including machinery operators, mechanics and engineers.
The mine would operate on weekdays from 7am until 7pm and on Saturdays from 7am till 1pm.
The site is located on gently rolling terrain mostly used for pastoral farming, on a terrace above the Clutha River.
Hawkeswood Mining said in its land-use consent application the proposal had been discussed extensively with the Clutha Gold Charitable Trust and a temporary alternative alignment of the trail had been agreed in principle.
It would be diverted around the mine site along Teviot Rd at times.
The mine would not impede users of the trail and it would be visible for less than 500m along it, the company said.
It also commented the area had a rich history of gold exploration, "and a working gold mine forms a modern part of that story".
The maximum area of the open mine pit would be 4ha at any one time.
A floating dredge is envisaged for when groundwater is encountered.
Gold-bearing wash would be processed on site and a gold recovery plant would be located on land near the active mine pit or on the floating dredge.
The company noted a paper road in the area was used by some people for access to the river for recreation and fishing.
Hawkeswood Mining intended to provide a separate temporary river access.
Part of the site is a former gravel pit used by the community for green waste.
Mr Johnstone said the company planned to take green waste and use it to help restore land once mining was finished.
Earthworks would not be closer than 10m to the river.
Millers Flat resident Graeme Young was worried about potential contamination of water.
"It puzzles me that a septic tank has to be 50m away from the river, yet they can mine to [up to] 10m of the river."
The company said the mining footprint avoided waterways.
