REPORT OP COMMITTEE ON PUBLICATION 89 



THE VINEYARDS OF THE COLUMBIA RIVER BASIN. 



By E. H. TWIGHT, 

 Guasti, California. 



The Grape Growing Districts of the States of Washington and Idaho are 

 found east of the Cascade Mountains on the bench lands overlooking the 

 Columbia River and its affluent, the Snake River (and its affluent, the Clear 

 Water) ; the Yakima, the Wenatchee and the Okanogan Rivers. 



The soil of those benches is either volcanic ash or decomposed granite; 

 these soils have made a reputation in growing some of the best apples in the 

 world and have now added to their laurels by producing grapes, that in color, 

 quality, flavor and even quantity are unsurpassed. 



The climate shows the usual effect of the Coast Range on the lands laying 

 east of it; very dry through the growing season and with a rainfall (of 6 to 

 14 inches) which takes place mostly in winter and in the shape of snow. 

 The Cascade Mountains being higher than the Coast Range further south 

 their effect is more striking and the trade winds from the Pacific Ocean, 

 heavy with moisture when they reach the coast, have abandoned nearly all 

 of it before they have overcome the great barrier of the Cascades. Thus 

 we find that at the mouth of the Columbia at Astoria the mean rainfall is 

 76.09 inches; at Vancouver, near the junction of the Willamette and the 

 Columbia, and only 90 miles up, the annual average rainfall has dropped to 

 45 inches, and just across the gorges through which the Columbia forces its 

 way through the Cascades, at the Dalles, 84 miles further up river, the rain 

 fall has dropped to 14 inches. The minimum is met a little further east near 

 Pasco, 300 miles from Astoria, where the Columbia swings north and receives 

 the Snake River from the east; here the mean annual rain fall is about 6 

 inches. Following the Columbia River north we find at Wenatchee 13.71; at 

 Brewster at the mouth of the Okanogan 13.52. If we follow up the Snake 

 River we find at Lewiston 13.48. 



From these figures it can be readily seen that grape culture in the Colum- 

 bia Basin can only be carried on with the aid of irrigation. It is true that 

 in many instances grape vines will grow without irrigation for the first two 

 or three years, but when they come into bearing they need water to give a 

 marketable crop. 



As regards the seasonal changes, we find that during the growing season 

 the hours of sunshine are probably greater than in the most favored districts 

 in the world. The days are long with hardly ever a cloud in the sky, from 

 early spring until fall. The summers are warm, the temperature reaching 

 sometimes over one hundred, and this insures a good supply of sugar in the 

 grapes. 



The fall brings a little rain, usually enough to help plowing, but it is 

 through winter that most of the moisture comes, a good deal of it in the 

 shape of snow. 



There are usually two or three cold spells in winter when the tempera- 

 ture may drop around zero, but with well matured wood most varieties stand 

 well; especially when there is a good coat of snow on the ground. 



