322 FORAGE ESTIMATES 



6. In forest mapping, the " strips " are run at least once and 

 usually twice to each 40-acre area. In range mapping, the strips 

 are never run more than once through a forty, and then only 

 through alternate tiers of 40 acres in each section. 



7. In unsurveyed country timber reconnaissance provides 

 that no more than 2 miles of line be run without an accurate 

 "tie-in." In grazing reconnaissance never less than 4 miles 

 and very often 6 miles of line is run before the " tie-in " is 

 established. 



8. The scale in timber mapping is 8 inches to the mile; in 

 range mapping it is never more than 4 inches and often only 2 

 inches to the mile. 



9. Timber estimates are determined by actual measurement 

 (diameter breast-high) of all trees on a 66-foot strip. Sufficient 

 measurements are made for the examiner to record the timber 

 production with a high degree of accuracy. In range recon- 

 naissance the estimate of ground cover and forage production 

 is entirely ocular, as the forage resources permit of no definitely 

 measured analysis. 



10. A description of the forest type is made for each 40-acre 

 area. In grazing work the description is made on the basis of a 

 section, though, to be sure, each type within this section is 

 described and its forage value shown. 



11. In timber mapping the descriptive report involves a dis- 

 cussion of the topographic and silvicultural management of each 

 unit area summarized statistically. The same general plan is 

 followed in range mapping, but with such changes or additions 

 as appear to be essential to meet the particular range problem 

 of the community. 



12. In timber reconnaissance the final map is on the scale of 

 4 inches to the mile, the types and other features being colored, 

 and contains all of the data recorded. In grazing reconnais- 

 sance the map is presented on a scale of 2 or 4 inches to the mile, 

 the types and other features being colored. A map drawn on a 

 scale of 2 inches to the mile is prepared in atlas form for the Forest 

 as a whole. In timber reconnaissance a crew of two or three 

 men work from one-fourth to one-half of a section per day, at a 

 cost of from 10 to 15 cents per acre. In grazing reconnaissance 



