Terence Clark says the search for remains at residential schools across Saskatchewan will not be an easy one.

Officially, there are 566 recorded deaths of students at residential schools in the province, but Clark, an assistant professor of archeology and anthropology at the University of Saskatchewan, believes the number will be much higher. He said officially, 4,100 children are unaccounted for, although that number could be as high as 6,000.

Last month, the Tk'emlúps te Secwépemc First Nation in British Columbia announced the discovery of what it believes to be the remains of an estimated 215 children buried on the grounds of the former Kamloops Indian Residential School.

Both Federation of Sovereign Indigenous Nations Chief Bobby Cameron and Premier Scott Moe have asked the federal government for financial aid in searching the grounds of all former residential school sites in the province.

However, Clark said due to the passage of time, some former residential school sites have become difficult to access, which will make documentation difficult in some cases.

"Many of these properties across the country have been sold off and they're in private hands," he said.

"And a lot of these sites have buildings now put on them and have been developed and so unfortunately some are just going to be very, very difficult to survey."

The professor has first-hand knowledge of this work, having assisted the Muskowekwan First Nation in a survey of its residential school graveyard, where the remains of 35 children were found.

As with the case in Kamloops, Clark used ground penetrating radar in his search at Muskowekwan, which sends radio waves into the ground, and is able to determine what materials are in the ground without disturbing anything.

He said many companies use the technology for everything from construction to building maintenance, but may not be able to do the fine work needed to properly document a graveyard. The Canadian Archaeological Association is working on developing guidelines that will help guide the process, as is Crown-Indigenous Relations and Northern Affairs Canada .

"I feel the rush right now is it is a bit dangerous and that we just want to make sure that the work is done to the highest standard," he said.

"I don't think it benefits the community to have people using the technology that aren't used to finding small, unmarked graves."

Ultimately, Clark said the work can be very difficult, but believes it's very important.

"I really worry that Canadians will get desensitized to this," he said.

"I'm hoping that everyone feels the pain of this every time, because the survivors do. Each of these children represents a traumatic event."