[Legate of Amon Lanc]

Interesting topic, and I believe I have a few thoughts to add to what has been said.

Originally Posted by Inziladun

The most recent would seem to be Elladan and Elrohir. They probably would have passed through Dunland when they rode with the Dúnedain of the North to meet Aragorn in Rohan.

Despite the counterpoints, I believe this may as well have been the case. Elladan and Elrohir might have been quite easily encountered by some Dunlendings, or seen by some hunters. They at least passed close enough, and we know that by that time the Dunlendings were a bit on the rise, possibly even roaming further around their usual borders. There is one more thought to it, if the Dunlendings started to become a bit more "cosmopolitan" at the times of their alliance with Saruman (meaning only that possibly from time to time a few were recruited to "military missions abroad" and then some of them returned back), the stories from farther lands (including also tales of Elves) might have been strenghtened among the common folk.

Originally Posted by The Might

After searching for an answer for some time now the only logical answer that I can give is that by saying "ever came to their country" Tolkien means Elves barely came to Dunland not just during the lifespan of the Dunlendings but ever since these people settled there in the first place.

This would make sense, since the ancestors of the Dunlendings, the Gwaithuirim who lived upon the Gwathló, surely must have known of the Elves living in Hollin back then.

As such, Elves wandering through the forests or on their way to Lórien around the Misty Mountains and not over the Redhorn Pass must have been encountered by the early Dunlendings, who perhaps feared them due to the perceived superiority of the Elves.

This knowledge would then have been passed down from generation to generation and would thus also be known in the form of myths by the late Third Age Dunlendings. They would then also fear the Elves and hide.

To me this makes sense since in M-e this often is the case - that old myths are still remembered by descendants. One example that comes to mind is the doubt of Eorl the Young concerning Lórien, also due to myths of that land being remembered within his culture as memories of when the Éothéod used to live in that area.

Then again, perhaps an easier answer exists...

I believe Miggy is right here, offering a very reasonable and down-to-earth point. I think this is the way it was, mostly, apart from unique cases like Elladan and Elrohir on their special mission, as mentioned above. However, I indeed believe that another answer exists as well, alongside this one. I do not believe that all that was to it were the old tales. I will say more of that further on.

Originally Posted by Fordim Hedgethistle

I find it interesting that the Dunlendings would be aware of the Elvish folk at all given that Elves are passing through the Shire all the time and nobody there seems to be aware of it. Perhaps the Dunlendings are more 'aware' than the hobbits (which would speak very much in their favour in contrast with the insular citizens of the Shire). I would argue that it's a more hopeful sign to see and then run away from than to be wilfully blind. But then again, I've never seen Elves myself, so what does that say about me...(?)

I don't think it's about being "more aware" at all. The hobbits also knew about the Elves, but it was only some of them. Remember what Sam Gamgee told to Ted Sandyman in the pub, that one can see the Elves at night passing through the Shire. I believe it might have been the same with the Dunlendings: a few "Sams", who were perhaps considered a bit weird by the majority of the population, did spot the Elves a few times, or at some times (might have been really rarely, even once a lifetime could be enough for some scared Dunlendings), but that's what kept the tales fresh.

Originally Posted by Tuor in Gondolin

A Gildorish wandering elf band does indeed seem possible.
Perhaps from Harlindon they wished to visit Fangorn forest or
take a winter non-mountain path to Lorien or Mirkwood.
Also, recall Treebeard's onservation that the Old Forest
was once more extensive, making an elf forest path across
Minhriath more attractive to them.

Of course, as Miggy already pointed out, there were really no nice forest paths from Lindon to Dunland anymore. But I am surprised why nobody yet thought of the most obvious reason for groups of "Gildor-ish" Elves to come near Dunland, near enough for the people to note them and be aware of their existence, but still in the way that it was enough to say that "a few indeed came to their country". My proposal would be - they indeed did not come to their country, but they could have been noticed by the scouts passing the neighbouring country, that is, Hollin! Wilderness, perhaps, but still a fair enough place for the Elves to make pilgrimages to, don't you think? I am not speaking of anything big here, but from time to time, somebody might have appeared - just like Gildor and his folk were going to the White Towers (and their journey was not a shorter one by any means). Remeber what Legolas said in Hollin, or, Eregion, as it used to be called? "I hear the stones lament them: 'Deep they delved us, fair
they wrought us, high they builded us; but they are gone.'" And Gandalf said: "Much evil must befall a country before it wholly forgets the Elves, if once they dwelt there." I believe even the Elves did not forget.