There are a few ways to say "snow-covered mountains" in Spanish, depending on the context and nuance you want to convey:

Literal translation:

* Montañas cubiertas de nieve: This is the most literal translation and works in most situations.

* Montañas nevadas: This translates to "snow-capped mountains" and emphasizes the presence of snow on the mountain tops.

More poetic options:

* Montañas blancas: This literally means "white mountains" and is a more evocative and poetic way to describe snow-covered mountains.

* Montañas de invierno: This translates to "winter mountains" and emphasizes the seasonality of the snow.

Ultimately, the best way to say "snow-covered mountains" in Spanish depends on the specific context and the desired effect.