How to use "boulders" in a sentence

There are also a lot of very large rocks called boulders, stuck between the canyon walls

If these boulders move or fall, they can be dangerous.

Stuck between them, as far as I can see, are boulders of different sizes

The boulders are both good and bad news

The bad news is that the boulders could move

I manage the first few boulders without any problems and reach another drop

The idea is to throw the rope over one of the boulders above my head