Stephen,
Looking back, I now see that the Railway Locomotives and Cars, Vol. 32, article on the Progress of Lieut. Beale's Wagon Road Route in 1859 that you referenced, was, as noted therein, an extraction of the Wanderer's Letter #6, published in The Press of Philadelphia on Nov. 7, 1859.
This fairly common "pass-thru" of news in those days of limited telegraphic reporting, shows the perceived importance around Philadelphia of the building of Beale's Wagon Road, its iron bridge construction, and the future development of a national railway route to California.
Thank goodness that the Wanderer was an astute observer and prolific writer; otherwise, we would have had very little eyewitness documentation of the six iron bridges actually built along the Beale Wagon Road in Indian Territory.