A massive search operation has been launched to find a 93-year-old man who went missing in Lanark County, west of Ottawa, earlier this week.

Geoffrey Leech was reported missing Wednesday after leaving a family cottage on Lakeshore Road in Highlands Township near White Lake to embark on a seven kilometre walk on a nearby hiking trail.

The retired geologist frequently took long walks in the area and help charted them during his career.

On Wednesday evening, OPP officers combed the woods with police dogs while a helicopter conducted an aerial search.

The search continued on Thursday with dozens of volunteers joining the effort to locate Leech.

OPP officers say it's crucial to find Leech as soon as possible. They worry he might be injured.

"We always hold out hope but we have to be realistic," said Insp. Gerry Salisbury. "It's been three days and we've got our fingers crossed."

Leech is described as a white man with blue eyes. He is about five-feet-nine inches and weighs around 130 lbs with a pronounced hunched-back. He was last seen wearing a baseball cap, a beige vest, a green shirt and brown khaki pants. He was also wearing hiking boots and likely had at least one walking stick.

Anyone with information about Leech's whereabouts is asked to contact the Lanark Detachment of the OPP at 613-267-2626.

With a report from CTV Ottawa's Joanne Schnurr