[Legate of Amon Lanc]

Originally Posted by Rumil

It would be natural, if Denethor trusted Saruman, to direct Boromir first to Rohan, then to Isengard, before trying to find Rivendell. If this had been done Boromir's journey would have been easier and he might have been able to get some information. Surely Saruman would be one of the best people to ask, as although Denethor might not have known he was on the White Council, he was obviously learned and long-lived, and on the way.

For some reason Denethor decided against asking Saruman, I reckon he must have been suspicious already.

I actually think so too. But not that he would be suspicious, like, really suspicious. I think it might have been something similar to Gandalf's "I might perhaps have consulted [the Ring with] Saruman the White, but something always held me back".

I would put three main reasons there:
1) some sort of pride (even though Saruman was "the" Wise and everybody knew that, Denethor would be the kind of person who would try to do things by himself if he could),
2) as mentioned above, "suspicion" (or something like that),
3) mere unwillingness to bother combined with the bit of disbelief that Saruman would actually know it either if the best of the Gondorians don't ("if something is not in our archives, it does not exist").

I think all these factors combined made Denethor (and consequently, Boromir) decide not to consult Saruman.

I wonder if Saruman ever met Thorongil?

I really doubt that. Thorongil operated mostly elsewhere (not in direct vicinity of Isengard, or not in any places where he would necessarily be forced to actually meet Saruman) and was really, really secretive. He would avoid exposing himself to more keen-sighted people than was necessary. Likewise, Saruman probably didn't have much of a special chance to meet Thorongil (such circumstances would be a bit unlikely to arise).

I guess the location of Rivendell was known to Denethor in very vague terms - ie somewhere near the end of the Great East Road before it crosses the Misty Mountains, but as has been said, its exact location was hidden. Even so Boromir lost his horse at the crossings of Tharbad, rather out of the way as the crow flies. Was he therefore heading up the Greenway to Bree and turning right, or did he cut across country up the Hoarwell? If he went through Bree, I wonder how this fits in with the timing of Frodo's journey?

Tharbad was at the time still the only good crossing of Hoarwell, and it was still on the road which was somewhat in use - or at least there were some remnants of a road. Referring back to Mith's post just above, if you can follow a road, you do it, especially in an unknown terrain. It is not that you can say "I will now turn and go fifteen miles northeast from here". You cannot do that even in the forest behind your house for a few hundred meters, unless you have a compass, and even then you must avoid thick bushes and whatnot. I think that much is obvious, so Boromir, if he could, would really prefer to follow the road as far as possible. It is actually more curious, as you say, that he didn't go to Bree, as that's actually what would make a lot of sense to do. But maybe this is where he got some directions, or knew that he should more or less try to follow the Greyflood. Who knows.