How long had it been since Howard had been on a horse?

According to Laura Hillenbrand's book Seabiscuit: An American Legend, Charles Howard had attended military schools in his youth, and it was then that he learned to be a skilled horseman. Later, he joined the cavalry and was in service during the Spanish-American war. When he bought the 17,000-acre ranch known as Ridgewood in 1924, Hillenbrand recounts that he rode a cow pony around the ranch. I didn't find anything in the book about how long it was in between his riding, but knowing he was born in 1877 and joined the military at 18, that would make it 1895. There was then a 30-year span of time before he became the owner of Ridgewood and was riding his cow pony around the ranch.
After the death of his son Frankie, Howard became despondent for a time. Later, he divorced his first wife as the marriage was severely strained after the loss of their child. He married his son's wife's sister, Marcela, and began to invest in his love of horses once again. In 1935, he helped a man named Strub build the Santa Ana Racetrack. He began to dabble in training and racing thoroughbreds. The book is mostly about the confluence of Tom Smith, Seabiscuit's trainer, and Red Pollard, his jockey, and how the unlikely combination of the three of them plus a horse who was too small became champions.