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~ solution. Information Collected by government of- fices, ins[1[utions and other groups could be used as a alternate source for baseline information with regulatory approval. After tonsu ltation with the regulatory authori- ties, PbM [hen requested that Technical Guideline Range Site Descriptions, developed by the local Soil Conserve[Lon Service es descrf bed in [he National Range Handbook (1476), be used to esta- blish revegetation success criteria. The Range S1[e Descriptions were to be used in conjunction with Order III soil au rvey information contained in the perm![ application to deve lop ~t he revegeta- tion etandarde. A technical meeting vas aubse-~ quen[ly held with the SCS in Gallup, New Nexico, a[ which revege[atian success standards were es- tablished for [he permit application. This approach [o revegetation success cri- teria deve lopmest allowed the permit app ileac ion review to go forward vlt hoot delay. OSN agreed that [he baseline data would be considered adequate io the permit application, since the SCS data col- lected for the development of the Range Site Descriptions were included by reference and could be reviewed if necessary. the mine are red Satrlbut ed at uniform depths and [here is no spatial handling of any particular Soil materiels. The generic reclaimed soil prof lie ar- rived a[ Ss a 9" layer of sandy loam [o clay loam topsoil, aver a 39" layer of subsoil ranging from clay loam [o clay. The profile was described from the surface to a depth of four fee[, [hie being con- sidered the effective rooting zone. Io phase three of the development, the generic reclaimed soil description was compared tm the nine Range Si[e Descriptions for the area. The generic profile from zero [o four fee[ moat closely reaem- ..bled the Loamy SCS Range Site Description. In the fourth and final phase of development, the Loamy Aange Site Description vas used to es- tablish [he revegetation success cr1 [aria for re- claimed lands a[ the mine. The etandarde eatabliehed included cover, production and diversity. T'he post- mining land uses, rangeland being primary and wild- life habitat secondary, were also taken into account when establishing the euccees standards and later when developing seed mixes to meet the success standards. Revege[a[ion Succeea Standards SCS RANGE SITE DESCRIPTION REVEGETATION SUCCESS STANDARDS AND DEVELOP10aNT Standards Development To establish the revegete [ion st anderds, PbM requested and received through [he NcKinley Soil and Water Conservation District, the help of Mr. Wayne F]se [h, Soil Conservation Service, Gallup, New Mexico. Nr. P]e[h's ind ep [h knowledge of [he rangelands in McKinley County and surrounding re- gion was an important contributor in [he establish- ment of the success crlt aria for HcK in ley Nine. The revegetation success Criteria development process involved four phases. In [he firs[ phase, all soil types iden [!f led et the mine by the Order III baseline soil inventory were 31st ed. A soil profile description for each mine soil mapping unit vas then compared with all range site soil prof ilea known to occur within the McKinley Mine region. This comparison resulted 1n the id entiflcation of nine range sites [ha[ ex 1St within the permit area. Although not necessary, vegetation information from [he perm It application and the Range SS[e Descrip- tions vas compared to ve rlfy the range sites cho- sen. The SCS Range Site Descriptions id en[lf led were Loamy (NO. 036A006N), Clayey Bottomlattd (No. 03613119N), Swale (No. 036AOI7N), Salty Bottomland (No. D36-6-N), Bottomlend (NO. D-36-118N), Loamy Savannah (No. 036AO15N), Shallow Savannah (No. 036A016N), Shallow Upland (NO. D-36-2N), and Flood P1a1n (No. D-36-BIN). In [he second~phaee~;~A~-gerteriC:wdf1'~pyufdlR!;~KF for reclaimed lands at the mine vas ecteblished. Only the A horizons of [he selvaged topsoils were considered in [his proceed. A single generic re- claimed soil profile was derived instead of se- veral profiles, since all topdrees Sng materials at The goal of revegetation efforts at the mine is to eatabll sh a rangeland grase(forb/shrub com- municy. The specific at andards for cover, pro- ductlvi[y and diversity for revegetation success are detailed below. Reclaimed lands at HcRfmley Mine must meet these etandarde after ten or more years of growth as dictated by [he regulations bse~ ed on annual prat lp ita[i on received. Cover Canopy cover for trees, sh rube end half-shrubs is to be a[ leas[ 10 percent. Basal cover for gras- ses and forbs 1s to be a[ least 25 percent. Both canopy cover for shrubs and basal cover for grasses and forbs were taken directly from page three of the Loamy Range Site Description. Production Annual production of above ground growth of perennial grasses and forbs, shrubs and half-shrubs must be at least 784 air-dry pounds per acre. The "90 percent of baseline productivity" factor ellov- ed by the regulations is already taken Into account and may no[ be used [o reduce Chie production a- mount. P6M initially proposed to use a eliding scale factor for [he production figure, keyed to annual precipitation for the yeere Sn which productivity measurements were taken for bond release. This ap- proach seemed reasonable~aince the Range Site Description indicated a range of 600 to 1,100 pounds of production per acre for unfavorable and Fevoreb le yee rs, respectively. When the effort [o eatab lieh the variable production standard became mired in bt ologlcal, tlimatologitel end technical complexi- ties, it became apparent that a fixed et andard would be [he only way to settle the production Sseue. _tt=_