300 CALIFORNIA DESERT TRAILS 



sky — that was all. But the scale on which these 

 elements were drawn, the unity and rhythm of line 

 and color, gave it the effect of a triumph of simplic- 

 ity in art. 



On reaching the eastern edge of the dunes I came 

 in sight of my next landmark, Pilot Knob. This is an 

 isolated peak five miles west of Yuma, and marks 

 the junction of the river with the Mexican bound- 

 ary. The usual route to Yuma here makes a circuit to 

 the northeast, but I knew that the railway touched 

 the river just east of this peak, and that a road from 

 Mexico came in there also. I therefore struck di- 

 rectly southeast for Pilot Knob (or, as it was named 

 by the Spanish explorers, the Cerro de San Pablo: 

 the present name, no doubt, dates from the days of 

 the fifties, when the river was navigated by flat- 

 bottomed steamboats, carrying the traffic of the 

 Arizona mines as far upstream as Ehrenberg). 



There was now some variety of scenery. To the 

 east was the southern end of the Chocolates, a red 

 and purple wilderness of low but rugged mountains, 

 and beyond them the higher ranges of Arizona, 

 strongly picturesque. A few palo verde and mesquit 

 trees grew at the margin of the dunes, but they soon 

 gave way to the everlasting creosote, burro-weed, 

 and ocotillo, with an occasional small ironwood. To 

 my surprise, the ocotillos were in full leaf, the result 

 of recent thunder-showers. To-day another storm 

 was preparing, and seemed likely to catch us miles 

 from shelter. Several times that morning I noted a 

 mirage, the common one of a sheet of pale-blue 

 water, with dark bushes showing here and there, the 



