Thank you Juraj for your response.
I had been using the edit.aspx as you showed above, however, then I needed to add some features from the Properties menu (eg. versions). Therefore, I wanted to leverage a cloned UIPage.aspx to utilize the built-in tabs of the UIPages.aspx page. I see the state stored in a session variable "SelectedTab|CMS.Content|Edit". Is there a an API method available to access that state?