Line 26: “Nothing out of fifty-nine” 1859 marked the peak of the Colorado Gold Rush.
Line 30: “Wagon-tenting” – Referring to the style of wagon with a canvas covered tent roof.
Line 31: “jade” - A contemptuous name for a horse; a horse of inferior breed, e.g. a cart- or draught-horse as opposed to a riding horse; a roadster, a hack; a sorry, ill-conditioned, wearied, or worn-out horse; a vicious, worthless, ill-tempered horse. (OED)
Line 32: “Squaw” – A North American Indian woman or wife (OED).
Line 50: “Arrowhead” – Could refer to Arrowhead, California, though is probably placed for emphasis on the Native-American connection (Melville’s home was called Arrowhead?).
Line 59: “Rio” – Referring to the Rio Grande river on the border of Texas and Mexio or Rio de Jainero in Brazil.
Line 61: “Indiana” – “Land of the Indians” in Modern Latin.