The Valiant Die Fast — Marshall Grover

To Reach The Bridge … The Killers Had To Get Past Big Jim!
Beyond that bridge was the west bank of the Rio Colorado -- beyond that the Utah border, and safety for the six gunmen who had looted the Delandro bank and ended the career of a veteran lawman.
Between the outlaws and that bridge stood Kell Garrard, gambler, man-hunter, son of the murdered sheriff, and Hurst, the dead sheriff's loyal deputy, and grinning Benito Espina, who was never really loyal to anybody.
And last, but never the least, the tall, tough and formidable Jim Rand, the relentless avenger whose deadly gun-skill was destined to increase the odds against escape.

Leonard Frank Meares (February 13, 1921 - February 4, 1993)
Sydney born Len Meares aka Marshall Grover, published around 750 novels, mostly westerns. His best-known works feature Texas trouble-shooters Larry and Stretch. Before starting to write, Meares served in the Royal Australian Air Force, worked in the Department of Immigration and sold shoes. In the mid-1950s he bought a typewriter to write radio and film scripts. Inspired by the success of local paperback westerns, he wrote Trouble Town, which was published by the Cleveland Publishing Company in 1955.
His tenth yarn, Drift! (1956), introduced Larry Valentine and Stretch Emerson. In 1960, he created a brief but memorable series of westerns set in and around the town of Bleak Creek. Four years later came The Night McLennan Died, the first of more than 70 westerns (sometimes called oaters) to feature cavalryman-turned-manhunter Big Jim Rand.