Possible Clues:

• Vegas casino named for an African locale
• About 3,500,000 square miles of Africa
• North African region
• Sand viper's home
• Name from the Arabic for "desert"
• The volcano Emi Koussi is its highest point
• Its name means 'desert'
• Desert of the Maghreb
• Bogart film set in the desert
• Desert north of the Sahel