Inspired by this (https://goo.gl/maps/NvPtF5E8ZKLU2PZs7), what are some examples far away trailblazers to a road in another jurisdiction? It could be state level or international level. State A has a trailblazer sign for State Highway B obviously in State B. You get it.
My first thought was exactly the one you linked.
Yukon 9 appears to be a little over 100 miles up Alaska 5 from its junction with Alaska 2. Shown June 14, 2001.
(https://www.teresco.org/pics/signs/20010614/ak2ak5yukon9.jpg)
Chesapeake Bay Bridge-Tunnel, 205 miles, on I-295 in Delaware (https://goo.gl/maps/3wdvAUaRcmxvTbga9). I recall there used to be another trailblazer for the Bridge-Tunnel on the southbound Jersey Turnpike somewhere near its southern end, but I don't recall the precise location, I'm not motivated to try to look it up on AARoads or elsewhere, and I don't know whether it still exists because I haven't been that way in several years.
There's the famous I-40 trailblazer on US 220 in Rocky Mount VA. 73 miles.
We did a variation on this a while back: https://www.aaroads.com/forum/index.php?topic=3085.0 so examples can also be found there.