SALEM, Ore. (AP) – Oregon will use ground-penetrating radar to search for bodies buried at the former Oregon State Insane Asylum.

The Statesman Journal reports Tuesday that the facility, which opened in 1883, once had a cemetery — but all the 1,500 bodies buried there were exhumed in 1913.

Now the Confederated Tribes of the Grand Ronde is asking the state to make sure that happened before a housing development gets built on the land.

There is no evidence that any remains were left behind, but the tribe wants a full accounting.

The Department of Administrative Services, which owns the land, is hiring a contractor to do the search.

The state will also conduct research about exhumations and cremated remains from the facility.