Riders work to keep cattle fever ticks confined to a quarantine zone LAREDO - This federal employee works along a treacherous stretch of high Rio Grande riverbank known as No Man's Land. His work uniform: leather chaps, sturdy Wranglers, high-top bullhide boots and silver spurs. His tools: a .357-caliber revolver, a lariat, a machete, a walkie-talkie and his beloved brown-and-white Appaloosa, Payaso. snip It's hard and lonely work in unforgiving terrain. The cowboys live away from their families in remote shacks four to five nights a week. They ride solo six or seven hours daily in 100-plus-degree temperatures, cutting trails...