I found some newspaper articles that might be of help.
I am a volunteer. I am not related. Ellie
Idaho Statesman November 12, 1916 Land entries have been filed in the United States land officeas follows: Homestead entries - James P. Marker, Emmett, 280 acres.
I don't know if this is your James Marker: Idaho Falls Times Dec. 27, 1917 Mr. and Mrs. James Marker are rejoicing over the arrival of twin boys at their home on the 22nd. Mother and the boys are doing fine, but Father Marker has some difficulty in tallying orders correctly the last few days.