In addition to the National Archives, you should check with the Library of Congress Motion Picture, Broadcasting, and Recorded Sound Division. The have the collection from NBC.
> On Feb 4, 2021, at 5:27 PM, Jerry Emory <[log in to unmask]> wrote:
> I'm writing a biography of George Meléndez Wright
> <http://www.pbs.org/nationalparks/people/nps/wright/>, the first Chief of
> the Wildlife Division of the National Park Service in the 1930s. He gave a
> radio presentation as part of the 1934 “National Parks Year” (declared by
> Secretary of Interior Ickes and supported by FDR): “Radio Talk Given By Mr.
> George M. Wright, Chief, Wild Life Division, National Park Service, At
> Washington D.C., June 27: ‘Big Game Of Our National Parks.’”
> He gave a second radio talk, also from Washington D.C., with Jay N. Darling
> (famous cartoonist and Chief of the Biological Survey) and his park service
> colleague Ben H. Thompson, on the "The National Parks Program!" Saturday
> May 4, 1935, between 3:15 to 3:45pm over a "National Broadcasting Company
> I have the transcript for both talks. Do any of you know if these were
> recorded, and if so, where they might reside?
> Many Thanks—Jerry Emory