1912 Indian Experimental Mail Carrier

Like many people, when I first saw the image above, I thought it was a Harley-Davidson Motorcycle Truck, albeit a little narrower than others I'd seen.  Then I came across this second image and it was clear that this was not a Harley at all, but an Indian!  Just like Harley-Davidson, Indian was vying for a share of the commercial motorcycle market and  US Postal Service in Washington DC experimented with this machine in 1912.  Coincidentally, Harley was testing their own motorcycle truck with the US Postal Service in Wisconsin during that same time.  Harley's test were performed during the winter of 1912, so based on these pictures I'd say Indian was delivering the mail first.
What's interesting to note about this machine is that it appears to be based on a 1906 - 1908 Indian Delivery Van.  It features a "camelback" gas tank over the rear tire, which was only used until 1908.  It also has the earlier diamond frame and not the more modern loop frame which came out in 1909.  Perhaps Indian had a surplus of pre-1909 machines or parts in their factory that they sold to the Postal Service for testing.

Based on the lack of images and information available on this machine, I would guess that the tests with the US Postal Service in Washington DC did not go well.  Most likely they switched to automobiles like many other postal systems.  If anyone has more information or photos of this interesting motorcycle, please leave a comment on this post.