Max Brand 
Dan Barry Series 

Max Brand (1892-1944) is largely known for his Western books and stories. He was very prolific and didn't limit himself to Westerns. He also wrote the Doctor Kildare stories which were the basis for the TV series of that name. He also used the pen names George Owen Baxter, Walter Butler, George Challis, Evan Evans, John Frederick, Frederick Frost, David Manning, and Peter Henry Morland. See also his wikipedia entry for more information on him.