Arizona at that time had two hosts: YUMA-SW (18.104.22.168) and YUMA-TAC (22.214.171.124), both on MILNET. The TACs (Terminal Access Controllers) were systems that allowed telephone dialup access to the network; they essentially played the role of a terminal server. The MILNET TACs developed a system for user authentication called the TAC Access Control System, or TACACS, which allowed a user to authenticate to a given TAC without the actual credentials being stored on the TAC. This protocol was enhanced by Cisco into XTACACS and then TACACS+, which is still used today, mainly on Cisco routers and switches. (The original deployment of TACACS meant that ARPANet users could not login using MILNET TACs--this is something that led to author and computer enthusiast Jerry Pournelle being kicked off the ARPANet in 1985 when his account on MIT-MC was shut down.)
There were a number of Multics systems on the net, including MIT-MULTICS in Cambridge, Massachusetts (10.0.0.6, through which I got access to ARPANet mailing lists back then), HI-MULTICS (10.1.0.94, the only host in Minnesota, belonging to Honeywell), USGS2-MULTICS in Colorado (126.96.36.199, belonging to the U.S. Geological Survey), and RADC-MULTICS (188.8.131.52, at the Rome Air Development Center in Rome, NY). The only hosts outside of the United States were MINET-RDM-TAC (184.108.40.206, in the Netherlands), MINET-HLH-TAC (220.127.116.11, in Scotland), FRANKFURT-MIL-TAC (18.104.22.168, in Germany--along with about 10 other hosts in Germany), three hosts in Italy, two in England, and three in Korea--all on military bases.