One expert described the situation as "the best for decades".
A fall in outbreaks of disease is thought to be the reason behind the trend and it was welcomed by Royal Society for the Protection of Birds spokesman Chris Harbard.
He said: "It was predicted earlier in the year that this would be a good one for grouse.
"But we have no real way of knowing figures until we get reports about the shooters bags. Grouse numbers do fluctuate and its nice to hear that they are up following some poor years."
Phil Pugh, North of England spokesman for the British Association for Shooting and Conservation, said: "Disease has been less of a problem than in previous years, and there is a mood of confidence that the present situation will continue into next season."
Grouse populations have also remained high in Scotland.
John Phillips, Director of the Heather Trust, said: "1997 was a good year for grouse, as predicted. In a number of places this season it was the best for decades."Reuse content