Data as at 18 October 2026 · from Western Australian Government registers and open data

Western Australian mining project · Operating

Lake Cowcowing North - West Dukin / Lake Hillman

Lake Cowcowing North - West Dukin / Lake Hillman is a Western Australian mining project (operating) in MINEDEX, owned by Lake Hillman Mining Pty Ltd 100%; Gypsum Supplies, on 7 current tenements held by LAKE HILLMAN MINING PTY LTD. Commodities: Gypsum.

MINEDEX project: J01451
Stage: Operating
Owners (MINEDEX): Lake Hillman Mining Pty Ltd 100%; Gypsum Supplies
Tenement holders: LAKE HILLMAN MINING PTY LTD
Commodities: Gypsum
Rehabilitation liability: Its rehabilitation liability is in the MCF Mining Index (subscribers): the Mining Rehabilitation Fund estimate, its trend since 2014, company provisions and closure-plan costs

Resources and reserves

Commodity	Resources	Reserves	Latest estimate
Gypsum	1.10 Mt at 94.4%, 1.0 Mt contained	—	25 September 2016

Current MINEDEX estimates over all the project's sites; resources may include reserves. MINEDEX (DMPE), CC BY 4.0.

Mine closure plans

Site	Operator	Latest plan approved	Plan (PDF on GeoDocs)	Closure year
Lake Cowcowing North - Gypsum	LINDSAY J & HELEN C STEPHENS, Lake Hillman Mining Pty Limited	7 September 2022	Lake Cowcowing North - Gypsum v5

Tenements

Tenement	Holder	Status	Expires	Commodities	Hectares
M 70/734 Mining lease	LAKE HILLMAN MINING PTY LTD	Granted	27 May 2034	Gypsum	19
M 70/1291 Mining lease	LAKE HILLMAN MINING PTY LTD	Granted	20 October 2037	Gypsum	9
M 70/1370 Mining lease	LAKE HILLMAN MINING PTY LTD	Granted	5 June 2040	Gypsum	109
L 70/110 Miscellaneous licence	LAKE HILLMAN MINING PTY LTD	Granted	21 February 2031	Gypsum	2
L 70/182 Miscellaneous licence	LAKE HILLMAN MINING PTY LTD	Granted	27 October 2037	Gypsum	2
L 70/183 Miscellaneous licence	LAKE HILLMAN MINING PTY LTD	Granted	27 October 2037	Gypsum	4
L 70/212 Miscellaneous licence	LAKE HILLMAN MINING PTY LTD	Granted	10 May 2041	Gypsum	1