In the spring and summer of 1950, Louis L'Amour wrote four stories about Hopalong Cassidy. He used the pen name Tex Burns and the books were commissioned by Doubleday's Double D Western imprint. The Rustlers of West Fork, Trail to Seven Pines, Riders of High Rock and Trouble Shooter were the first four novels that he had ever published.
But for the next thirty-eight years he denied that he had ever written any of them.
For more information go to: http://www.louislamour.com/novels/hopalong4byLouis.htm