I cannot give you any link to info on this, as i got it from a friend in the system and i do not wish to drop them in it.
Essentially,
the Gorge is fairly narrow and very deep. The aim is to stop traffic transitting the gorge below the upper levels of it. Apparently they are concerned about geological stability and potential damage from helicopter and fixed wing noise, and also annoying the hikers at the bottom of the gorge.
Potential restrictions maybe 1500' and 3 miles from the centreline of the bed of the gorge.
Track from anywhere N/W of the gorge to Ingelara(main strip in the area), will take you through the proposed restriction.
Highest point is around 4500'.
The airspace ownership issue came up when I asked whether QNPWS had the power to restrict this airspace. Straight out Restriction, does not equal the spirit of a Fly Neighbourly agreement.
I was told that they had had legal opinion that they owned from "Core to Ozone".