I found where Clyde married a second wife.
Clyde Ray Isenburg, 21
Residence: Ashton, Fremont Co., ID
married in Salt Lake City 1 Aug 1922
Erma Lee Fox, 21
Residence: Lamad, Ponnce, Kansas
Certificate #AO40182, FHL No. 429,119
Source: Western States Marriage Record Index.
I haven't been able to find anything about Ada neither her marriage or death. Maybe her death wasn't included in the death index. The state of Idaho began collecting death information at the state level in July, 1911.
Death certificates are on microfilm at the Idaho State Historical Society Library and Archives, www.history.idaho.gov/archives-research-requests
There is always the possibility that they divorced. Divorces are handled by the local district or probate court. Contact the Fremont County Recorder if they have divorce records that early. Successful Searching!