Cowley said he has not made contact with his family, who are working with the community and authorities to bring him home.
Yesterday, dozens of his friends and family searched around the geothermal area, but did not find him.
“Thank you again to everyone who helped,” Cowley posted to Facebook.
“It was physically and emotionally draining for everyone, and we appreciate every effort more than words can say.”
Cowley asked supporters to focus on distributing flyers within Tokoroa and the surrounding towns.
“Every action helps - thank you for standing with us,” she wrote.
The Waikato Times reported Dean is a teacher at Tokoroa Intermediate School.
Board of trustees chair Tracey Ramanui told the Waikato Times the school was committed to supporting Dean’s friends, family and colleagues.
“The board and school leadership are united in providing ongoing care for all affected, and we appreciate the understanding and support of our community.”
Police encourage anyone who has seen Dean or knows where he may be to contact 105, referencing file number 251003/5935.