Born underground, grown inside a rocky womb
The earth is our cradle; the mountain shall become our tomb
Face us on the battlefield; you will meet your doom
We do not fear what lies beneath
We can never dig too deep
Bernadette didn't actually plan for things to turn out the way they did.
Entrance to the mountains.
It began with what seemed to be a modest deposit of copper ore up the mountainside where the Black Forest biome begins to shade into the Mountain. Like a lot of "modest" deposits in this game, this one was much bigger than it seemed on the surface and digging it all out involved removing a large chunk of the mountain side.
At this point she thought: why not just keep digging? There didn't seem much chance that she would simply happen on some silver ore by chance, but then again, there hadn't seemed much chance of finding iron ore by random digging in the swamp... and she had found some. Plus, nothing ventured nothing gained, and the dig site is close to her new mountain-border base.
So she began to dig. It got colder as she progressed, and soon she had to start using the frost-resistant mead. Incidentally, it is extremely stupid for the game to make you wait until after the first dose of a potion expires before you can take the next dose. Most games allow for a bit of overlap, since the transition can come at an awkward time, but in Valheim you'd better be there right as the clock hits zero or you begin to freeze. Silly.
The narrow road to the Deep North....
Anyway, Bernadette literally dug out of the Black Forest and into the Mountain. Soon there was a sound of wolves, and then two of them dropped in, literally. Since the trench at that point was about five meters deep, both of them took damage on landing and they didn't seem to know what to do in a very narrow space where there was no chance they could flank Bernadette or attack in any other way than straight ahead. They were confused, and she soon discovered that a good sharp blow with the pickax stuns them. In less than a minute, both of them were rug material and she had another fang as well. She took less than 10% damage since between being stunned and getting into each others' way, the wolves had made a complete mess of defending themselves.
And so it went as she dug. She has killed about ten wolves so far and only one of them put up any kind of a fight, since it managed to drop in at a place in the path where there was a bit of room to manoeuvre. Even then, it did her very little damage. Another ended up literally standing on Bernadette's head, but it had the usual difficulty in this game of attacking things that are situated lower than its level and died as quickly as all the others.
Stairway to heaven.
She's glad they showed up, since their skins, teeth, and one Wolf Trophy are welcome. She's not yet sure whether she will get any other profit from the exercise. Not finding silver is not a real surprise -- it's emphasized that you have to have the Wishbone from defeating Bonemass before you can count on that -- but she's still not uncovering or finding any rocks with obsidian either. The terrain in the Mountain biome is very irregular and the "bedrock" level, deeper than which you cannot dig, reflects that, so at one point she had to set up a workbench and build a ladder to get up the slope.
Now let's see how much of the mountain she has the patience to tear down before she decides to give up and go get that wishbone from the far-distant Bonemass way over on his damned island.