Looks like the domain is for sale. Here is an old view of the site from February 2020 for anyone else, like me, who didn't know about it. I saw the reference on a scenario pack in the Just Trains store and went to look it up. EDIT: I swear I did not capitalize that R in the domain there, the topic auto-edited itself when posting. Nice assumption. LOL
Yeah, it's really frustrating the auto-captilising of OP title headers! Often simpy confusiong things for everyone - it doesn't even make things look neat & tidy (just odd looking), so not quite sure the point. lol RRYard haven't been active now for the bet part of 7 years (the last thing they poduced being their scenario extension pack). Their old website hadn't been touched for many years, & there were no further TS creations since 2013 (or at least to my best of my knowledge). Once they agreed to sell their main product the King's Arm Highway Deluxe route via the Just Trains store - I'm guessing the owners of RRYard no longer saw the point in keeping their own old website going. I'd imagine once the current domain & web hosting period came to end, the authors likely decided simply not to renew it. I might be entirely wrong - but would personally be very surprised to see the site return. The King's Arm Highway was a most enjoyable fictional route creation in the early days of TS; though things have certainly moved on since. Some of the game's early DLC including RSC's Train v Zombies series bring back some fond memories.
The blogspot seems to be still available https://railroadyard.blogspot.com/2011/10/kings-arm-highway-deluxe-oct092011.html Lone Wolf Don was quite prolific back in the day, but hasn't published anything in years.
Oh hey! I found it searching for one of the free packs from the site. It's located over at Mystic Sword. http://www.mysticsword.com/rryard.com/index.html Only issue: the free packs don't work. Trying to figure out where to get that Horseshoe Curve one, particularly.
I did get in touch with him. I was able to acquire the free content. The only question is whether he would be willing to have the content hosted elsewhere. I suggested Just Trains as they already host and sell two of his packs, and having free downloads can't necessarily hurt because it could be seen as goodwill. While that's not my business to decide, I hope the content does go somewhere, and I'll see if I can make the proper files available when I do have a chance to play them.