324 FORAGE ESTIMATES 



mated. ^ Likewise, the size and location of the different plant 

 types is not exact. However, as the types almost invariably 

 overlap more or less, it would be possible to locate them only 

 approximately, even if the work were done much more accurately 

 than it usually is. 



Further, the exact character and density of the type varies 

 according to the time in the season when the examination is 

 made. An area examined in the spring, for example, might shovi 

 the presence of certain annual plants, such as dog's-tooth violet 

 (Erylhronium), Douglas kno tweed {Polygonum), and onion 

 (Allium). If the area were examined in the autumn, the annual 

 species would not be noted, as they dry up and disappear early 

 in the summer. However, a good average estimate of the more 

 important permanent constituents of the plant cover is recorded 

 if the mapping is done at any time during the growing season. 



Furthermore, the map does not always show the exact con- 

 ditions when lands are sketched as " poorly stocked," or as hav- 

 ing inadequate watering facilities. If land is sketched as poorly 

 stocked, that does not necessarily imply that there is insufficient 

 palatable vegetation. The cover may be ample and of high 

 forage quality; but the area may be so steep or so strewn with 

 down timber, or, indeed, it may be so swampy or otherwise so 

 inaccessible as to be of little grazing value. 



Again, areas may be classified as inadequate in water supply 

 if they are examined late in the autumn; whereas, they would be 

 listed as having ample water if they were examined early in the 

 season before the temporary springs and seeps had dried up. 

 Furthermore, a classification of " ample water," reported by the 

 examiner in the spring, might hold for wet seasons; or, the classi- 

 fication of " poorly watered," as listed by the same examiner, 

 might be reliable for dry seasons. Then, too^ as the examiner 

 passes rapidly over his course, he may fail to record some spring 

 or watering trough inconspicuously situated and thus show the 

 conditions regarding water more serious than they really are. 

 Therefore it is a good plan to reexamine, casually at least, all 



^ Sometimes these cultural features may be located with the use of maps in the 

 county surveyor's office or in the Land Ollice. On unpatented claims, of course, 

 no complete maps are available, and the features must be estimated by the examiner. 



