A number of his works are listed on the National Register of Historic Places for their architecture.
[1] His father, Edward F. Riley (1847–1927) was secretary of the University of Wisconsin Board of Regents from 1888 to 1906 and was a prominent member of business and real estate circles in Madison.
In 1897 he relocated to Boston to study architecture at the Massachusetts Institute of Technology, where he remained until 1900.
From 1914 to 1941, Riley designed houses in Madison suburbs such as Nakoma, University Heights, and the Highlands, and in neighboring Shorewood Hills and Maple Bluff.
He also designed a number of fraternity and sorority houses on Langdon Street and some important nonresidential and institutional buildings in Madison.