What is "upper kalskag"

Population (2000): 230
Housing Units (2000): 66
Land area (2000): 3.781858 sq. miles (9.794968 sq. km)
Water area (2000): 0.350237 sq. miles (0.907110 sq. km)
Total area (2000): 4.132095 sq. miles (10.702078 sq. km)
FIPS code: 81320
Located within: Alaska (AK), FIPS 02
Location: 61.537440 N, 160.316070 W
ZIP Codes (1990):
Note: some ZIP codes may be omitted esp. for suburbs.
Headwords: