TULSA, Oklahoma - The City of Tulsa said Thursday the conversation about mass graves from the 1921 Race Massacre potentially being near or under the Inner Dispersal Loop has not been discussed extensively until this week.

Crews are searching four areas based on research done by the state commission in the late '90s and early 2000s.

Deputy Mayor Amy Brown said the city decided to start the investigation by revisiting those locations with newer technology. The City said Thursday it has asked the Oklahoma Archaeological Survey to also scan the trail area between Oaklawn Cemetery and the IDL.

Reverend Robert Turner, who is on the Public Oversight Committee for the investigation, told News On 6 earlier this week there are "very credible leads" about bodies being dumped near and right underneath the overpass of the interstate near Oaklawn Cemetery.

The Oklahoma Archaeological Survey said Wednesday with so much rebar in the highway, its technology likely would not pick up on anything in that area.

"The problem with doing any work there primarily for us is the radar pulse goes through the ground, but it's really affected by metal. And the fact that there's so much rebar that's put in the concrete in highways, especially in those bridges, it’s gonna cause a lot of problems for our machine and I just don't think we're gonna be able to penetrate it,” Senior Researcher Scott Hammerstedt said.

Deputy Mayor Amy Brown said the city is still making an effort to collect stories, oral history, and records from people who might have information on other possible locations.

"We've received quite a few historical narratives about some other cemeteries in Tulsa, some other potential locations. The challenge, for us, really comes when we try to substantiate those locations. We're looking for multiple interviews, or multiple records, or multiple oral histories that kind of point to the same location,” Brown said.

The Oklahoma Archaeological Survey team will continue scanning Oaklawn Cemetery and trail area near the IDL Monday, October 14. The team will then move on to Newblock Park Tuesday and Wednesday.