Yes it is. I heard on the Trainz Italia forums that if you PM; Jango; for 35 dollars he will send you the files. As for it being available publicly anymore sadly it is not. But that is how I obtained it. It really only works/looks good/functions in TANE and Below (Best suited for TS12) I think it has been taken down because a couple of the items are faulty/wont load in TANE and above. In 19/22 the trees are all faulty and most of the bridges/tunnels are as well. Only thing in TANE is the snowsheds are not faulty but don;t show up. There are like 4 tunnel portals and 4 bridges that either wont load or are faulty. But the route is still playable in it. Still looks good in TANE.
I believe he is working on Donner Pass for TRS19/TRS22 but the last progress pics I saw were back in 2019. I think he had to finish West from Denver for TRS22 first.
Its worth a try