Balrog Breaking and Entering

[Inziladun]

I thought I'd bring to light something I recently found that would have some bearing on this. Apparently it would have been easier than I'd thought for the Balrog to make its way under Moria without being noticed.

Here the Elven-way from Hollin ended. Holly was the token of the people of that land, and they planted it here to mark the end of their domain; for the West-door was made chiefly for their use in their traffic with the Lords of Moria.

FOTR A Journey In the Dark

The Tale of Years says Eregion was founded in the year 750 of the Second Age, so the West-gate through with the Fellowship entered Moria was not in existence at the time the Balrog would have been fleeing Thangorodrim.
With such a prosperous Dwarven city which surely held commerce with others east and west, you'd think it must have been accessible from the western side of the Mountains though, and presumably there were other ways in.
I still have yet to figure out why the Balrog chose the Misty Mountains near Moria as a hiding place. You'd think the Grey Mountains would have been much better. After all, they seem to have been pretty much left alone by Elves, Men, and Dwarves, and the remaining Dragons apparently made the Withered Heath in those mountains their home after the fall of Morgoth.

[Legate of Amon Lanc]

But at the time when he was supposed to get there, I would assume the doors were also guarded? I mean, even though the door was open, you would have a Dwarf or two sitting there, if nothing else, and it would be somewhat awkward for the Balrog to get through customs.

As for the Grey Mountains/Withered Heath question, well, maybe that's just it - without the central leadership, maybe the Balrog did not feel as comfortable to share his place with some dragons. No, it would be somewhat "let's stay each in our own territory, here be dragons, here be spiders, here be balrogs". Also, what do we know, maybe Durin's Bane had a special affinity for mithril?

And one more note to the Grey Mountains - it's not that they were totally left alone either. Dwarves have been there at some point too, and possibly (maybe) already Men on the southern side (the Northerners lived there certainly later, resp. then the ancestors of Rohirrim). And Orcs (at least around Gundabad, so probably outreaching to the western part of the Grey Mountains).

[Findegil]

I don't think that the way to the Westgate existed prior to the Elves founding Eregion. If you think about the way of the company it looked for a long time as if they wandered through a very simple tunnel system with no much choice of direction. Only when they aproach the eastern area of Moria things become more complex. In addition the dwarves did use the redhorn-pass frequently. Otherwise it wouldn't have gained such a bad reputation. Why would they have used the pass if they had an underground way?

I think that the passage quoted means that not only tha gate was build at that time but the entire entrance and the way to reach it.

Respectfully
Findegil

[William Cloud Hicklin]

I would add that Moria's extent and population at the end of the First Age were not what they would later become. Others have pointed out that the West Gate wasn't built until SA 750 or later; and Gandalf towards the end of the journey calls the East End "Old Moria." Remember that Moria's population was greatly swelled in the early Second Age by refugees from Nogrod and Belegost.

[Fordim Hedgethistle]

Talk about slipping in through the perhaps-non-existent or perhaps-existent-but-non-functioning wings...