Father Curley chose a site on the college grounds, planned the building, and supervised its construction to its completion in 1844.

He was responsible for the installation of the 12-inch equatorial telescope with which for twenty years he observed and gathered data on variable stars.

In 1989, as part of GU's bicentennial celebration, Professor Donald M. Spoon, who had a lab in the Observatory at the time, organized the dedication of the garden.

At the time, the garden was full of hundreds of iris species and cultivars, including new ones that Professor Spoon had bred.

Currently, Observatory Hill likely has thousands of species of archaens, bacteria, and eurkaryans, including animals, fungi, plants, and protistans.