An aerial 1080 drop in the Dart, Routeburn and Caples Valleys is expected to take place tomorrow.
The Department of Conservation (Doc) will drop poison-laced baits over about 20,000ha of public conservation land encompassing Dart Valley, Beans Burn, Rock Burn, Routeburn, North Branch Routeburn, Caples Valley, and Kay and Fraser Creeks.
Doc yesterday advised affected concessionaires, recreation and community groups that all walking tracks in the area will be closed tomorrow, for up to 24 hours.
The road to Chinamans Bluff will be closed from the forest edge at the top of Mill Flat from late today and throughout tomorrow.
If necessary, the operation will continue on Saturday.