The Clemuel Ricketts Mansion was added to the National Register of Historic Places in 1983.

Colley Township is home to the Clemuel Ricketts Mansion on Ganoga Lake, listed on the National Register of Historic Places, and part of Ricketts Glen State Park.

At the 2010 census there were 694 people, 214 households, and 116 families living in the township.

The population density was 11.9 people per square mile (4.65/km2).

[5] Of the 214 households 12.6% had children under the age of 18 living with them, 45.3% were married couples living together, 5.6% had a female householder with no husband present, and 45.8% were non-families.

At the 2000 census there were 647 people, 179 households, and 95 families living in the township.

[6] Of the 179 households 14.0% had children under the age of 18 living with them, 44.1% were married couples living together, 5.0% had a female householder with no husband present, and 46.4% were non-families.