The couple run about 11,000 merino sheep on Glenmore Station.
The 1900ha station runs from the shore of Lake Tekapo up to Aoraki/Mt Cook National Park, Mrs Murray said.
"It keeps us busy and out of trouble."
A ram merino fleece from the station won them the grand champion prize at the show on Friday.
The couple won the supreme prize at the show last year, which was the first time they had entered the competition, Mrs Murray said.
"It was good to defend the title," Mrs Murray said.
The fleece weighs 8.3kg greasy and won two other competition classes — champion stud merino ram and champion stud fleece.
Winning the competition helped promote their business selling stud rams.
Some new clients had bought rams from them as a result of the win last year, she said.
"So we thought we’d enter again."
The wool from their flock was sold to Devold Wool Direct Ltd to make "casual apparel" in Norway, she said.
Fleece competition judge Craig Smith, of Wanaka, said he gave the fleece 99 points — a single point shy of the perfect score of 100.
"The fleeces entered this year were absolutely magic — it was a difficult competition to judge," Mr Smith said.
Show chief wool steward Martin Paterson said more than 180 fleeces had been entered in the competition.
"It’s the most we’ve had in recent years."
The fleeces were entered from farms between Blenheim and Stewart Island.
An increase in the "quality and weight" of the fleeces from non-pedigree flocks was "pleasing".
"The flock guys are getting more conscious of getting more wool out of their sheep by breeding and feeding — that’s coming through loud and clear."
The grand champion winner was a "stunning fleece".
