including occasional stands of mature or over- 

 mature ponderosa pine averaging smaller than 22 

 inches; large, pure (20)0, approximately 80 per- 

 cent or more, by volume, ponderosa or Jeffrey 

 pine; large ponderosa-sugar pine (20A), 22 inches 

 d. b. h., or more, 20 to 50 percent sugar pine; 

 small (21). containing at least 1 M board feet of 

 ponderosa pine 12 inches d. b. h., or more, and 

 comprising either (a) selectively cut stands of any 

 age, or (b) immature "bull pine," usually 12 to 22 

 inches d. b. h. but including occasional immature 

 stands of more than 22 inches; seedlings, saplings, 

 and poles (22), on old burns or heavily cut-over 

 land, less than 12 inches d. b. h., containing less 

 than 1 M board feet per acre of saw timber, if any. 



No. 20B. Sugar pine mixture, large; sugar pine 

 containing 20 percent or more by volume, pon- 

 derosa pine less than 50 percent, usually in mix- 

 ture with Douglas-fir, ponderosa pine, or white 

 fir; most of the volume in trees more than 22 

 inches d. b. h. 



Nos. 23 and 24. Fir-hemlock: Noble fir, Pacific 

 silver fir, alpine fir, Shasta red fir, white fir, moun- 

 tain hemlock (or, occasionally, western hemlock), 

 or any combination of these species composes at 

 least 50 percent of the volume of the stand. The 

 two size classes, characteristic of the upper slopes 

 of the Cascade Range, are large (23), most of the 

 volume in trees 12 inches d. b. h., or more, and 

 sawlog material (other mature stands ordinarily 

 classed as subalpine, No. 33); small (24), dominant 

 trees mostly less than 12 inches d. b. h., usually 

 young trees on old burns. 



Nos. 25, 26, and 26A. Lodgepole pine forests 

 containing at least 50 percent by volume of lodge- 

 pole pine, often almost pure, the three types cor- 

 responding to size class of most of the dominant 

 trees as follows: Large (25), 12 inches d. b. h., 

 or more; medium (26), 6 to 10 inches; small 

 (26A), less than 6 inches. 



Nos. 27 and 28. Pine mixture: Characteristic 

 of north slopes and cooler basins and consisting 

 of about 20 to 50 percent by volume of ponderosa 

 pine with a variable quantity of western larch, 

 white fir, Douglas-fir, lodgepole pine, western 

 white pine, or other species, or of any combina- 

 tion of these species. The two types recognized 

 are large (27), including forests in which most of 

 the volume is in trees 12 inches d. b. h., or more, 



and in which cutting has been immaterial; and 

 small (28), in which dominant trees are mostly 

 less than 12 inches d. b. h. 



Nos. 21)/2 and 28 3/2. The two types of the 

 upper-slope mixture are characteristic of the colder, 

 moister sites and are ordinarily above the ponde- 

 rosa pine zone and contain only a negligible quan- 

 tity of that species; variable proportions of western 

 larch, white fir, alpine fir, Douglas-fir, Engelmann 

 spruce, lodgepole pine, western white pine, and 

 occasionally other species; where Engelmann 

 spruce, western white pine, or larch forms 50 per- 

 cent or more of stand by volume, mapped as a 

 separate subtype (273^ ES); large (273^), most of 

 volume in trees 12 inches d. b. h., or more; small 

 (283^2), dominant trees less than 12 inches d. b. h. 



Nos. 29 and 30. White fir: 50 percent or more 

 by volume of grand or white fir, usually within the 

 range of ponderosa pine, and segregated into large 

 type (29), having most of the volume in trees 12 

 inches d. b. h., or more, (over 150 years); and 

 small (30), most of the dominant trees less than 12 

 inches (under 150 years). 



Nos. 31 and 31 J^. Hardwood types, in which 

 maple, aspen, cottonwood, etc., predominate, 

 pure or in mixture; large (31^), 12 inches d. b. h., 

 or more; small (31), less than 12 inches d. b. h. 



No. 33. Subalpine: Alpine fir, mountain hem- 

 lock, Shasta red fir, lodgepole pine, whitebark 

 pine, western white pine, and alpine larch pre- 

 dominating and usually interspersed with meadows 

 and glades. At upper limits of tree growth, 

 usually unmerchantable because of poor form and 

 small size. No volume recorded. 



Nos. 35A and 35B. Nonrestocked cut-over: 

 Logged areas not satisfactorily restocked (less than 

 10 percent) or a residual stand of less than 1 M 

 board feet per acre and put to no other use. Dif- 

 ferentiated by age: (35A) cut 1920 or since; (35B) 

 cut before 1920. 



Nos. 37, 37B, and 37W. Deforested: (37) Uncut 

 stands killed by fire and not restocked, remaining 

 green timber, if any, being unloggable; (37B) simi- 

 larly deforested by insects, (37W) by wind throw. 



No. 38. Noncommercial rocky: Within range of 

 commercial timber, below limits of subalpine type, 

 too rocky, steep, or sterile to produce a stand of 

 commercial availability, size, density, or quality; 

 any species; unlikely ever to be of commercial value; 



