The mountainous region has important oil deposits, as well as natural gas, limestone, gypsum, sulfur, and other minerals. Its mineral waters have made it a spa center. Agriculture is concentrated in the Terek and Sunzha river valleys. Oil, petrochemicals, oil-field equipment, foods, wines, and fruit are produced. The population, which is concentrated in the foothills, is predominantly Chechen, or Nokhchi. The Chechen, like the neighboring Ingush, are Sunni Muslim, and speak a Caucasian language.