Chase Township is a civil township of Lake County in the U.S. state of Michigan. The population was 1,194 at the 2000 census.The unincorporated community of Chase is the only significant population center in the township. Chase is located where U.S. Highway 10 crosses the Middle Branch of the Pere Marquette River at 43°53′21″N 85°38′08″W / 43.88917°N 85.63556°W / 43.88917; -85.63556. The post office in Chase serves ZIP Code 49623, which includes most of the northwest part of Chase Township as well as the southwest portion of Pinora Township, the southeast portion of Cherry Valley Township, and the northeast portion of Yates Township.Both the community and township were named after Salmon P. Chase, the Chief Justice of the United States at the time the area was being settled in the 1860s. The community was first known as "Greendale", which was recorded through clerical error as "Green Dale". A post office was established with the name of Chase in March 1872.