Where does “Первоуральск” come from?

Первоуральск (Russian) comes from Russian пе́рвый — first.

Ancestry of “Первоуральск”, step by step

Первоуральск traces back through two separate lines of ancestry.

via Russian пе́рвый

StepLanguageWordMeaning
1Russianпе́рвыйfirst

via Russian Ура́л

StepLanguageWordMeaning
1RussianУра́лUrals (mountain range)
Every word from Russian пе́рвый