1920 - The local fraternity of Sigma Delta became Alpha Tau Omega Delta Eta Chapter

1921 - The newly formed ATO Chapter moved into a larger house on 129 South Meldrum. They would stay in the house until World War 2 pulled several men away from higher education and left several fraternities with few members.

1950 c. - ATO moves into a new house, now Caninos on 613 South College Avenue. Following World War 2, several fraternities experienced strong growth

1960 c. - The men would move into the corner of Birch & Shields until the mid 90s

2006 - The chapter recolonized and quickly grew to re-establish itself as a dominate fraternity of CSU