I was finally able to get some pictures of what appears to be an AT&T Long Lines build along the side of old US Route 66, several miles west of Seligman, AZ.

There are three pairs of open wire, with the conductors of each pair spaced at what looks like 8 inches apart. The insulators look like clear CD 155s on pins, and clear spools on the transposition brackets.

AT&T referred to CD 155s as "DP" insulators, and the spools as "span transposition bracket" insulators. See: http://www.insulators.info/specifications/att-1958-january.pdf.

See the article at http://www.insulators.info/articles/openwire/ for a picture and description of this kind of construction.

I took a number of pictures through the window of a tour bus returning us from a jeep tour to the bottom of the Grand Canyon. My new circular polarizer eliminated the window reflections. On these two pictures I seem to have nearly compensated for the motion of the bus. Most of the rest were blurry.

I'll return in a week to take some more from a non-moving platform!