The ruling clears the way for construction of the 350-kilometre line to carry wind-generated electricity between Lethbridge, Alberta, and Great Falls, Montana.
The project is spearheaded by Calgary-based Montana Alberta Tie Ltd., wholly owned by Toronto-based Tonbridge Power Inc.
The company says construction could start later this fall on the line, which could carry 300 megawatts at capacity in both directions.
The landowners had been seeking leave to appeal an Alberta Court of Appeal ruling from earlier this year.
The Appeal Court had said Alberta's energy regulator was right when it said it didn't have the power to re-examine the location of the line's corridor, which had been approved by the National Energy Board.
Bob Williams, a company vice-president, said engineers will take farmland into account when building the lines.
"We've designed in extra clearance where a line goes over irrigated land so that the irrigation systems can operate safely right underneath the line," he said. "We've also [tried] to place the individual poles so they are out of the way of the irrigation pivots."
The project was approved more than a year ago by both the Alberta and Montana utility commissions after years of public consultations and environmental assessments.