Horse of a Different Color: Reminiscences of a Kansas Drover, originally published in 1968, is the eighth (and final) book in the Little Britches series.
From the 2002 audio book:
In the early 1920's cowboy and dry-range farmer, Ralph Moody, found himself with mountainous debts through the collapse of the livestock market, and the dealings of a crooked partner. He faces the choice of declaring bankruptcy before he turns twenty, or working off the intimidating balance against him. His fortunes seem to be turning when a flash flood takes all he owns, and he is forced to auction off his farm and animals.
Ralph never surrenders, but finds a way to turn tragedy into opportunity. Overhearing a conversation on a railroad supply contract, he decides to place a bid. Winning the contract and digging himself out of debt, he also saves a Kansas town from total bankruptcy...
The Dry Divide