A band of limestone outcrops on the east side of Lower Arrow Lake, 0.8 kilometres south of the Broadwater Post Office. The limestone has been correlated with the Pennsylvanian to Permian Mount Roberts Formation or (according to the Geological Survey of Canada Open File 1969) an unnamed Ordovician to Devonian unit. The band continues eastward up the mountain side for at least 400 metres and possibly up to 8 kilometres. The band is 150 metres wide on the lake. Bedding strikes 065 degrees and dips 55 degrees southeast.

The band consists of medium to coarse grained, grey and white thin bedded limestone containing some silicates and pyrite. Argillite interbeds occur on the south side of the deposit. Numerous randomly orientated dykes intrude the limestone on the north side. A sample taken across the entire lake side exposure contained 51.55 per cent CaO, 0.35 per cent MgO, 6.62 per cent insolubles, 0.26 per cent R2O3, 0.20 per cent Fe2O3, 0.045 per cent MnO, 0.016 per cent P2O5, 0.03 per cent sulphur, 41.06 per cent ignition loss and 0.13 per cent water (Minister of Mines Annual Report 1959, p. 173, Sample 7).

A small quarry was opened up on the deposit near the lakeshore, 46 metres from the southern edge of the limestone band. The limestone was used to manufacture lime sometime earlier this century but no production figures are available.