A Yukon prospector, and a local contractor, will each pay $1,200 for building a 17-kilometre trail without permits.
The fines were delivered in Yukon Territorial Court on Wednesday.
Prospector Nicolai Goeppel pleaded guilty to three charges under Yukon land use regulations. The trail was built last summer near McGregor Creek, about 45 kilometres north of Carmacks.
H. Coyne and Sons, the excavating contractor that did the work, also pleaded guilty to three charges under territorial land use regulations.
The government says the trail is about 3.5 metres wide and leads to a remote prospecting lease that was still pending approval. Most of the trail was cut through Crown land.
"This is one of the worst offences Yukon has seen in terms of contraventions of land use in recent years," said Crown prosecutor Megan Seiling.
Judge Peter Chilsolm said the trail "far exceeded the area where Mr.Goeppel had staked," but acknowledged that Goeppel had shown remorse by contacting the Little Salmon/Carmacks First Nation to apologize, and had cooperated with law enforcement.
The trail was never subject to an environmental assessment before being built and was discovered by a local trapper.
Defence blames 'lack of clarity' and government delays
Goeppel's lawyer, Richard Fowler, argued the case was due to a "lack of clarity," and not a disregard for rules.
Fowler described a mining culture in Yukon where miners sometimes start work based on informal promises.
"Work was encouraged to begin before permits were issued, because of delays in issuing permits. That's because the work season is short," he said.
He told the judge that work was done based on informal assurance from the region's mining recorder.
"This is not an individual who just blindly went and built a road. He was in frequent contact with the mining recorder. Mr. Goeppel believed what he was doing was OK," Fowler said.
Crown prosecutors had argued for the maximum allowable fine under territorial land use regulations, which would have been $1,500 ($500 each, for the three charges), but Fowler argued that would have been excessive.
Environmental damage, First Nation says
The Little Salmon/Carmacks First Nation had complained that the trail interfered with a trapline, and caused environmental damage.
On Wednesday, the Crown sought to have a Natural Resources Officer testify to describe environmental damage, but the court denied the request.
The lawyer for H. Coyne and Sons, meanwhile, argued that the company did the work in good faith, believing permits had been granted to Goeppel.
But the judge found the company had an obligation to "verify the work was lawful."
Goeppel and the company will each pay a $180 victim surcharge as well.
Goeppel declined comment exiting the courtroom.