Just to the north of there they were rising up from 6000ish up near Gladstone, and near Maryborough up to 7500 and becoming 8/8ths. After that I had decided to stay VFR and go under, so I have no facts on any closer, but it could have been getting more like 9000' as a guess.
morno was in the hold at MLY at the time. He might remember.