These ridges mark the northern edge of the Red River Valley, and offer a different geological atmosphere.
ðiːz ɹˈɪdʒᵻz mˈɑːɹk ðə nˈɔːɹðɚn ˈɛdʒ ʌvðə ɹˈɛd ɹˈɪvɚ vˈæli, ænd ˈɔfɚɹ ɐ dˈɪfɹənt dʒˌɪəlˈɑːdʒɪkəl ˈætməsfˌɪɹ.