The Collaborative International Dictionary of English v.0.48:

Woolstock \Wool"stock`\, n.
   A heavy wooden hammer for milling cloth.
   [1913 Webster]

U.S. Gazetteer Places (2000):

Woolstock, IA -- U.S. city in Iowa
   Population (2000):    204
   Housing Units (2000): 101
   Land area (2000):     1.031998 sq. miles (2.672863 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    1.031998 sq. miles (2.672863 sq. km)
   FIPS code:            87015
   Located within:       Iowa (IA), FIPS 19
   Location:             42.566730 N, 93.845030 W
   ZIP Codes (1990):     50599
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Woolstock, IA
    Woolstock