The family of 27-year-old Jessica Boyce are concerned since she went missing in Marlborough last week.
Police are appealing for information regarding Ms Boyce's whereabouts.
She was last seen on Tuesday 19 March. Her vehicle was located at Lake Chalice which is in Mount Richmond Forest Park.
"We are seeking information on Jess' movements in the weeks leading up to her disappearance, particularly Jess' actions and activities throughout the Blenheim and Renwick areas," Constable Al Hendrickson said.
"We wish to speak to anyone who has been up the Lake Chalice Road since it recently re-opened."
Anyone with information is urged to contact Blenheim Police on (03) 578 5279.