District 3.-The principal species in mixture are yellow pine and white fir. Usually at medium altitudes between the yellow pine and Engelmann spruce types.

District 4. The principal species in mixture are western yellow pine, lodgepole pine, and western larch. Usually at medium elevations between the yellow pine and lodgepole pine or Engelmann spruce types.

District 5.-The principal species in mixture are yellow pine, sugar pine, incense cedar, and white fir. Usually at medium elevations on fairly favorable sites. Nearly always on north and east slopes or moist bottoms.

District 6.-The characteristic forest west of the Cascades. occurring as pure stands of Douglas fir, or Douglas fir mixed with hemlock, cedar, and other species, such as Sitka spruce, Lawson cypress, grand fir, western white pine, silver fir, and rarely lodgepole pine.

Douglas Fir-Spruce.

District 4.

A stand containing approximately 60 per cent or more of Douglas fir and Engelmann spruce in varying mixtures. Other species in mixture are western yellow pine, lodgepole pine. and western larch. Usually at medium elevations between the yellow pine and the lodgepole pine or Engelmann spruce types. Cedar-White Fir.

District 1.

A stand composed of cedar and white or grand fir, the former nearly pure in patches; the latter predominant throughout. with a considerable amount of Douglas fir, some yellow pine in groups on the knolls and as scattered individuals throughout. and rare western white pine individuals. The type occurs on the Selway National Forest and the southern portion of the Clearwater National Forest south of the commercial range of white pine.

Cedar-Hemlock-White Fir.

District 1

A stand composed of cedar, hemlock, and white or grand fir in varying proportions, with a little white pine, also Engel mann spruce, alpine fir, and rarely Douglas fir. Areas which

under management could be made to produce white pine in commercial quantities.

Larch-Douglas Fir.

Districts 1 and 4.

A stand containing approximately 60 per cent or more of western larch and Douglas fir with white or grand fir in mixture. Larch is the key tree. The proportion of larch varies greatly, from very little to practically pure.

District 1.-The principal species in mixture is yellow pine, occasionally with lodgepeople pine, western white pine, lowland fir, western red cedar, or western hemlock. Usually at medium elevations, about the same as Douglas fir, but on more favorable sites. On less favorable sites than white pine.

District 4.-The principal species in mixture are yellow pine and lodgepole pine, white or grand fir, and Engelmann spruce. Usually at about the same elevation as the Douglas-fir type, but on slightly more favorable sites.

White Fir-Larch-Douglas Fir.

District 6.

A stand containing approximately 60 per cent or more of western larch, white fir, grand fir, and Douglas fir, with some western yellow pine and lodgepole pine, but with yellow pine in the minority. Within its range western larch is the key tree. The proportion of each species varies greatly, from very little to practically pure. A prevalent type on the north and cool slopes within the yellow-pine zone; of secondary commercial importance and very variable mixture.

Western Hemlock.

District 6.

A stand containing approximately 50 per cent or more of western hemlock, usually in mixture with one or more of the following: Douglas fir, western red cedar, grand fir, and silver fir. Found west of the Cascades on situations similar to those on which the Douglas fir type occurs; also on higher situations. Cedar.

District 6.

A mixed forest in which cedar is the important commercial species, usually comprising 40 per cent or more of the stand, the

associates being hemlock, grand fir, silver fir, Douglas fir, and sometimes a little Sitka spruce. It is found principally in valley bottoms on either side of the Cascades, but chiefly on the west side, contiguous to the Douglas fir or the western hemlock type. Districts 1, 2, 3, and 4.

Engelmann Spruce.

A stand containing approximately 50 per cent or more of Engelmann spruce. Sometimes follows a temporary type of

aspen.

Districts 1, 2, and 4.-Engelmann spruce may be pure, but is more often in mixture with alpine fir, lodgepole pine, limber pine, Douglas fir, and occasionally, in District 2, bristlecone pine. Usually at the higher elevations and on the moister sites.

District 3.-Engelmann spruce may be pure, but is more often in mixture with alpine fir, Douglas fir, bristlecone pine, or corkbark fir. At the higher elevations, usually at the upper limit of timberland.

Sitka Spruce.

District 6.

A stand composed predominantly (usually at least 60 per cent) of Sitka spruce. It is found chiefly on valley bottoms and benches on the west side of the Olympic and Coast mountains.

Fir.

Districts 3, 4, 5, and 6.

A stand containing approximately 50 per cent or more of one or more species of the true firs. White fir, alpine fir, red fir Shasta fir, noble fir, and silver fir, either in combination or singly, usually predominate, with grand fir in smaller quantities.

District 3.-A stand containing 50 per cent or more of white fir. The chief tree in mixture is Douglas fir, associated with Engelmann spruce, alpine fir, and cork-bark fir at the higher elevations, and with yellow pine at the lower elevations.

District 4-A stand containing approximately 60 per cent or more of white fir, alpine fir, or grand fir, either in combination or singly, with a varying mixture of Douglas fir, Engelmann spruce, and lodgepole pine. It is found at varying elevations,

depending on the exposure, within the Douglas fir and Engelmann spruce zones.

District 5.-A stand containing approximately 50 per cent or more of white fir, red fir, or Shasta fir; often in mixture with western white pine, sugar pine, mountain hemlock, and lodgepole pine, the last scattered or in pure patches; occasionally mixed with Jeffrey pine, incense cedar, and Douglas fir. At the higher elevations and on cool, moist sites.

District 6.-A stand characterized by noble, silver, Shasta, or red fir, either in mixture or singly. Other species in mixture are Douglas fir, western hemlock, mountain hemlock, western white pine, lodgepole pine, white fir, grand fir, western larch, and yellow cedar (C. nootkatensis). It is the characteristic type of certain situations on the upper slopes of the Cascades, usually above Douglas fir and hemlock types on the west and above the yellow pine and white fir-larch-Douglas fir types on the east of the Cascades. The key trees are silver fir and noble fir in the northern part and Shasta fir and red fir in the Southern part of the district.

Red Fir.

District 5.

A stand containing at least 75 per cent of red fir (Abies magnifica) or Shasta fir (A. shastensis), usually at the higher elevations below the subalpine type.

Mountain Hemlock.

Districts 1 and 6.

A stand containing approximately 50 per cent or more of mountain hemlock (T. mertensiana). Other species common in the mixture are alpine fir, silver fir, Shasta fir, alpine larch (L. lyalli), white-bark pine, lodgepole pine, western white pine, and Engelmann spruce. At the higher elevations usually hear the upper limit of tree growth. Areas of mountain hemlock not capable of producing merchantable stands should be included in the subalpine type.

District 1.-The principal species in mixture are alpine fir, Engelmann spruce, and western white pine.

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District 6.-The principal species in mixture are alpine fir. silver fir, lodgepole pine, alpine larch, and western white pine. Subalpine. Districts 1, 2, 3, 4, 5, and 6.

A stand containing a varying mixture of subalpine species, no one of which is abundant enough to throw the stand into any of the types already described, or rarely pure stands. At the upper limit of tree growth, usually unmerchantable because of poor form and small size, and of value for protective pur poses only.

District 1.-The principal species are alpine fir, Engelman: spruce, lodgepole pine, white-bark pine, limber pine, mountai hemlock, and alpine larch.

District 2.-The principal species are alpine fir, Engelmano spruce, lodgepole pine, limber pine, and bristle-cone pine. District 3.-The principal species are Engelmann spruce bristle-cone pine, limber pine, and dwarf juniper.

District 4-The principal species are alpine fir, Engelmann spruce, lodgepole pine, white-bark pine, and limber pine.

District 5.--The principal species are red fir, Shasta fi white fir, lodgepole pine, white-bark pine, western white pine foxtail pine, and mountain hemlock.

District 6.-Usually characterized by alpine fir, but not neces sarily containing a majority of this species: also has Shast fir, noble fir, lodgepole pine, white-bark pine, western white pine, mountain hemlock, and alpine larch. It is a type which does not produce saw logs.

Redwood.

Districts 5 and 6.

A stand containing approximately 80 per cent or more of red wood, usually with some Douglas fir, madrone, tanbark oak, and other smaller hardwoods. In situations at low elevations along the coast in California and southern Oregon.

Aspen.

Districts 2, 3, and 4.

A stand containing approximately 60 per cent or more of aspen, often nearly pure, but sometimes with various conifer: in mixture. At medium to high elevations, but usually on fairly