The Maine Warden Service has taken all leads “as far as we can go” in the search for missing Appalachian Trail hiker Geraldine Largay, a spokesman said Wednesday.

While the search for the missing Tennessee woman continues, the Maine Warden Service needs more trained searchers because of the difficult terrain in the area, said Cpl. John MacDonald.

The Warden Service continued to use volunteer searchers on Wednesday, but Wednesday night announced it is now seeking only searchers who are affiliated with the Maine Association of Search and Rescue. The organization is a nonprofit group that provides training and certification for search and rescue volunteers using nationally recognized standards, MacDonald said in a news release.

“If we just pull people in that have hiked in the past and are interested in helping us, we’d have our work cut out for us,” MacDonald said in an interview earlier in the day. “We need people that, because of the terrain, are formally trained in search and rescue.”

An “intensified search strategy” will be put in place this weekend, according MacDonald.

The Warden Service is also using national cellphone analysis experts to try to track down Largay. Wardens are still urging the public to help.

MacDonald said it’s up to the commissioner of the Department of Inland Fisheries and Wildlife and the colonel of the Maine Warden Service to decide how long the search continues and that “it’s not going to be an easy decision.”

MacDonald said officials still hope to find the hiker who called the Stratton Motel at 5 p.m. July 24. The female caller “made a statement regarding ‘Inchworm’ (Largay’s trail name) being overdue in meeting with her husband, George.”

Searchers took to the air Tuesday, nine days after Largay last talked to her husband. About 60 searchers continued looking for Largay, 66, of Brentwood, Tenn., who started her hike in April, 950 trail miles south in West Virginia.

Largay’s husband, George, had been following her progress via text message throughout her trip. On July 21, Largay left Sandy River Plantation near Rangeley and texted her husband that she was on top of Saddleback Mountain. Largay sent a text to her husband the next morning and planned to meet him in Wyman Township, about seven miles north on the trail, the next day, but she never arrived.

Police ask anyone with information about Largay to call the Public Safety Dispatch Center in Augusta at 800-452-4664.

Jesse Scardina can be contacted at 861-9239 or at jscardina@mainetoday.com.