Added July 2024: … The Above Google Street View, Shows The Likely ZMM Narrator’s Grangeville Idaho Restaurant, Which In At 126 East Main Street ,Grangeville, ID.
…ON The Main Highway Rt-13, Which Practically Goes Straight West, Through This Small Town.
…Now Named “The Three Mile Restaurant”, This Is The Only 1960’s Style, Soda-Fountain Restaurant, Which Could Be The ZMM Narrator’s “Deep Cool Inside. ”

The ZMM Narrator says =>
…“Highway 13 follows another branch of our river but now it goes upstream past old sawmill towns and sleepy scenery. … At the top of the plateau at Grangeville, Idaho, we step from the blasting heat into an air-conditioned restaurant.”

Rt-13, Grangeville, ID.

NOTE:
…When Henry Gurr was at this restaurant, June 2002, it was closed and was unable to get photos of inside the building. … And when here in July 2024 we were able to get a good noon meal & take many photos, but due to camera failure, they got gone.
…Fortunately however, Goole found the NEXT 7 photos. Showing what this restaurant looks like inside.

File = GoogStVu ThreeMileR. estaurant E.MainGrangevillID.jpg