The Socorro Field Office

Record of Decision

for the

Resource Management Plan

Cooperating Agencies: 

The Pueblo of Zuni

Catron County

The Bureau of Land Management

Albuquerque District

Socorro Field Office

Socorro, New Mexico

August 2010
IN REPLY REFER TO: 

1617 (02000) 

 August 20, 2010 

Dear Reader: 

This Record of Decision (ROD) approves the Resource Management Plan (RMP) for the Socorro Field 

Office. The preferred alternative (with modifications) in the Proposed RMP is the selected alternative in 

this Resource Management Plan. The plan provides guidance for managing approximately 1.5 million 

surface acres and 6 million acres of Federal mineral estate in Socorro and Catron counties. 

This plan was prepared under the regulations implementing the Federal Land Policy and Management Act 

of 1976 (43 CFR 1600). An environmental impact statement was prepared for this plan in compliance 

with the National Environmental Policy Act (NEPA) of 1969. 

The ROD approves new designations concerning oil and gas leasing and development, Off-Highway 

Vehicle (OHV) designations, land tenure decisions, special designations, Visual Resource Management 

(VRM) classes, and avoidance and exclusion areas for rights-of-way. These decisions are intended to 

replace the goals, objectives, management actions, and conditions of use described in the 1989 Socorro 

RMP. 

Copies of the ROD and the RMP can be obtained on the web at http://www.blm.gov/nm. Thank you for 

your interest and participation in the development of the plan. If you have any questions about the ROD, 

please contact Kevin I. Carson, Planning Team Leader, at (575) 838-1280. 

 Sincerely, 

 Linda S.C. Rundell 

 New Mexico State Director

United States Department of the Interior

 BUREAU OF LAND MANAGEMENT

New Mexico State Office

301 Dinosaur Trail

P.O. Box 27115

Santa Fe, New Mexico 87502-0115

www.blm.gov/nm
Socorro Resource Management Plan i Record of Decision

Table of Contents

I. INTRODUCTION................................................................................................................................................... 1

II. DECISION............................................................................................................................................................. 1

DESIRED FUTURE CONDITIONS..................................................................................................................................... 2

LAND USE ALLOCATIONS (ALLOWABLE USES).................................................................................................................. 2

MANAGEMENT ACTIONS ............................................................................................................................................ 2

III. OVERVIEW OF ALTERNATIVES............................................................................................................................ 2

IV. ALTERNATIVES CONSIDERED BUT ELIMINATED FROM DETAILED ANALYSIS...................................................... 3

V. MANAGEMENT CONSIDERATIONS IN SELECTING THE APPROVED RMP ............................................................. 4

VI. MITIGATION MEASURES .................................................................................................................................... 4

VII. RMP IMPLEMENTATION AND MONITORING.................................................................................................... 4

VIII. PUBLIC INVOLVEMENT AND COOPERATING AGENCIES ................................................................................... 5

IX. GOVERNOR’S CONSISTENCY REVIEW................................................................................................................. 6

X. RESULTS OF THE PROTEST REVIEW ..................................................................................................................... 6

XI. AVAILABILITY OF THE PLAN................................................................................................................................ 8

APPENDIX 1: LEGAL DESCRIPTION OF HORSE SPRINGS CONSERVATION EASEMENT............................................... 9

APPENDIX 2: EXPLANATORY NOTE: THE HISTORY OF AUMS AND RELATED LAND ACQUISITIONS IN THE SOCORRO 

FIELD OFFICE .......................................................................................................................................................... 10
Socorro Resource Management Plan 1 Record of Decision

I. Introduction

This Record of Decision (ROD) approves the Socorro Resource Management Plan (Approved 

Socorro RMP) for the Bureau of Land Management’s (BLM) administered public lands under 

the jurisdiction of the Socorro Field Office. The Approved Socorro RMP is described as 

Alternative B in the Proposed Socorro RMP/Final Environmental Impact Statement (EIS) 

explained in this ROD. This ROD provides the background regarding the RMP’s development

and the rationale for approving the proposed decisions contained in Alternative B. It also 

describes the clarifications and minor decision modifications made to the Approved RMP based 

on comments received during the governor’s consistency review process, as well as the protests

received on the Proposed RMP/Final EIS.

II. Decision

The decision is made to approve the attached Socorro RMP for the BLM-administered public 

lands located in Socorro and Catron Counties in New Mexico (see Map 1 in the Approved

RMP). The RMP updates relevant decisions in the 1989 Socorro Resource Management Plan

concerning special designations; land tenure adjustments and realty actions; rangeland resources; 

oil and gas and other minerals; renewable energy; vegetation management; visual resources; 

outdoor recreation; off-highway-vehicle designations; cultural, archeological, and paleontological resources; special status species; and wildlife habitat.

The RMP was prepared under 43 CFR 1600, which implements the Federal Land Policy and 

Management Act of 1976 (FLPMA). An accompanying Environmental Impact Statement (EIS)

was prepared for the Approved RMP in compliance with the National Environmental Policy Act 

of 1969 (NEPA) and associated regulations. Management decisions and guidance for the public 

lands managed by the Socorro Field Office are presented in the RMP attached to this ROD.

RMP-level decisions covered by the ROD are land use planning decisions that were protestable 

under FLPMA during the plan development process. The decisions identifying travel routes 

within designated areas for motorized vehicles are implementation decisions and are appealable 

under 43 CFR Part 4. Those decisions are contained in Appendix J of the RMP. (Consult the 

Federal Register Notice for the Socorro RMP’s Record of Decision and the appropriate 

regulations at 43 CFR, Part 4, Subpart E for appeal requirements.) The Approved RMP also does 

not contain decisions for actions outside the jurisdiction of the BLM or other decisions dealing 

with actions implementing the RMP. (Refer to the RMP implementation and monitoring section

below for additional information.) In addition, complying with existing statutory requirements,

national policy, and identifying budget allocations to implement the RMP are not plan decisions.

The RMP decisions will also not change the BLM’s responsibility to comply with applicable 

laws and regulations. 

The RMP’s decisions will be implemented upon approval of this RMP. The plan decisions 

include desired future conditions, allowable uses or land use allocations, and management 

actions. Brief descriptions of the RMP’s decisions are provided below.
Socorro Resource Management Plan 2 Record of Decision

Desired Future Conditions

The Socorro RMP identifies desired future conditions or outcomes in terms of goals and 

standards for resources and use. They direct the BLM’s actions in effectively meeting legal 

mandates, numerous regulatory responsibilities, national policy, BLM State Director guidance,

and other resource needs. 

Land Use Allocations (Allowable Uses)

Management actions and land use allocations are the primary means to achieve the plan’s goals.

The Socorro RMP identifies land use allocations that allow, restrict, or exclude certain activities 

or uses on BLM’s public land and mineral estate. The RMP’s land use allocations include, but 

are not limited to, decisions for lands and realty (e.g. avoidance/exclusion areas for rights-ofway)

1

; fluid and solid mineral development (e.g. closed, open, open with restrictions); visual 

resource management classes (e.g. VRM I-IV); BLM public lands identified for acquisition, 

retention, and disposal; and special designations such as Areas of Critical Environmental 

Concern.

Special designations include Congressional or administrative designations. Congressional 

designations include, for example, wilderness and national scenic and historic trails (e.g. 

Continental Divide National Scenic Trail). Although these designations are not RMP-level 

decisions, management actions in the Socorro RMP have been identified to meet the objectives

established for the applicable areas.

Administrative designations made by the BLM in the RMP primarily include, for example, Areas

of Critical Environmental Concern (ACECs) and Special Management Areas (SMAs). ACECs 

and SMAs respectively have unique historic, cultural, scenic, and/or natural values, or other 

resource values. These administrative designations therefore have accompanying management 

prescriptions that are designed to meet those resource objectives.

Management Actions

Management actions help attain the RMP’s established goals and objectives. They include 

measures that will be applied to guide day-to-day activities on BLM’s public lands, including 

actions to maintain, restore, or improve land health. The RMP also identifies management 

actions that identify stipulations, other mitigation measures, and best management practices.

III. Overview of Alternatives

Four alternatives were considered and analyzed during the RMP’s development (Draft RMP/EIS 

and Proposed RMP/Final EIS): the No-Action Alternative (Alternative A) and Alternatives B, C, 

and D. The alternatives are distinguished primarily by the degree of protection or use of the 

resources and they are summarized below.

No-Action Alternative (Alternative A) represents the continuation of existing 

management plans, policies, and decisions as established in the 1989 Socorro RMP and 

 

1

The total avoidance and exclusion areas in the Approved RMP have been respectively corrected from 347,950 acres to 341,763 acres and 

406,283 acres to 406,289 acres due to a geographical information system technical error. 
Socorro Resource Management Plan 3 Record of Decision

subsequent amendments. The No-Action Alternative is required by NEPA and serves as 

the baseline for comparison against the other alternatives.

Alternative B (the Proposed RMP) represents a balance of resource use and conservation

and is the Approved RMP with the modifications noted in this ROD. Management under 

this alternative would balance the need to protect, restore, and enhance natural values

with the need to provide for the production of food, fiber, and minerals and to provide 

recreation, heritage tourism, and other services on public land. This balance would be 

achieved within the limits of the ecosystem’s ability to provide resources on a sustainable 

basis and within the constraints of applicable laws and regulations. Measures to protect 

sensitive resources would be less restrictive than under Alternative C. 

Alternative C places a greater emphasis on resource conservation, protection, and 

enhancement of natural and cultural resources than Alternative B. This would be 

achieved primarily through increased management emphasis on protection of resource 

values associated with special designations and special status species. In some areas, 

commodity production would be excluded to further protect sensitive resources. 

Alternative D emphasizes commodity production and use, including mineral leasing and 

mineral material sales, grazing, commercial recreation and tourism, and woodland

products harvesting. Under Alternative D, constraints on commodity production would be 

the least restrictive while still complying with applicable laws, regulations, and BLM 

policies. Potential impacts on sensitive resources would be evaluated on a case-by-case 

basis.

The alternatives considered during the planning process reflect different management actions and 

land use allocations. For example, for ACECs and SMAs, Alternative C generally has the largest 

number of acres dedicated to special designations, and is the most restrictive on resource uses;

therefore Alternative C is the environmentally preferable alternative. Alternatives D and B

identify progressively less acreage for special designations, and generally have less restrictive 

ACEC management prescriptions. The RMP identifies specific management prescriptions for 

ACECs and other special designations to further address motorized vehicle use, realty actions

and other land use authorizations, and mineral management. 

IV. Alternatives Considered but Eliminated from Detailed Analysis

Several alternatives were considered but eliminated from detailed analysis. A variety of areas 

were considered for special designations; however, only those areas meeting the BLM criteria for 

ACECs of relevance, importance, and need for special management were identified in some of 

the alternatives. Some alternative management strategies were considered, including various best 

management practices, development of watershed management plans, and development of 

partnerships. These decisions can be implemented at any time without amending or revising the 

RMP; therefore, they were not included in the alternatives. Other proposed management 

strategies, such as maintaining vegetative cover and soil conditions, are managed under the New 

Mexico Standards for Public Land Health and Guidelines for Livestock Grazing Management 

(New Mexico Standards and Guidelines), which were carried forward in the Approved RMP.

Lastly, some management strategies were considered but eliminated because they were outside 

the BLM’s jurisdiction.
Socorro Resource Management Plan 4 Record of Decision

V. Management Considerations in Selecting the Approved RMP

Compared with the other alternatives, the Approved RMP (Alternative B as modified) provides 

the best balance between resource use and conservation consistent with the BLM’s policy 

guidance and requirements, including the multiple use and sustained yield mandate of FLPMA 

and the New Mexico Standards and Guidelines. 

The decision to select the Proposed Alternative as modified is also based on:

The combination of management actions that are needed to address the planning issues 

and planning criteria identified during the planning process;

The analysis of the alternatives in the Draft RMP/EIS and Proposed RMP/Final EIS; 

The Governor’s consistency review and protest process; and

The diversity of community needs and public/stakeholder interests that have been 

expressed throughout the planning process concerning the future management of the 

Socorro Field Office administered public lands and mineral estate. One rational for 

selecting Alternative B is to address these diverse needs and concerns in a fair manner,

while providing a practical and workable framework for the future management of BLM 

New Mexico’s public lands. 

Compared to the No-Action Alternative, the Approved RMP contains management decisions that 

are expected to improve resource conditions, result in more consistent management of the 

recreation and public access programs, and promote resource protection within the Socorro Field 

Office. 

VI. Mitigation Measures

The Approved RMP’s decisions considered all affected resources and uses needed for future plan 

implementation. Reasonable measures to avoid or minimize adverse environmental impacts are 

built into the RMP where practicable and appropriate. Many of the standard management 

provisions will reduce or minimize impacts when applied to future activities proposed in the 

planning area. The New Mexico Standards and Guidelines also provides guidance for mitigating 

adverse impacts on resources where livestock grazing is identified as the cause. (For additional 

information on mitigation and best management practices, refer to RMP’s appendices C, H, and I 

and management decisions by program area.) 

VII. RMP Implementation and Monitoring

A Socorro RMP Implementation Strategy has been developed to guide implementation of the

plan’s decisions. The strategy is a working document and identifies priorities for management 

actions and activities that will be implemented in the Socorro Field Office area over time given 

available resources. Examples include preparing activity plans for ACECs and other special 

designations, a travel management plan for the Socorro Field Office area outside of WSAs, as 

well as an activity plan for the Gordy’s Hill Special Recreation Management Area. Many of the 

RMP’s implementation management actions dealing with site-specific projects or activities will 

require further environmental analysis as required by NEPA during the plan implementation 

process. Additional measures to mitigate environmental impacts may also be developed during 

subsequent analysis at the activity-level stages, or through legally mandated consultations to 
Socorro Resource Management Plan 5 Record of Decision

address future proposed actions in the planning area. The BLM will continue to involve and 

collaborate with the public, local, state, and other Federal government agencies, and Native 

American tribes during implementation of this plan. 

Effectiveness monitoring is the process of collecting data and information to determine whether 

the RMP’s desired outcomes are being met or progress is being made toward meeting them. 

Monitoring also allows management activities to be adjusted, if certain land health or resource 

goals are not being attained. Wildlife habitat and special status species, rangeland resources, 

invasive/noxious weeds, recreation, cultural resources, realty actions, special designations, and 

other resources and uses will be monitored over the life of the RMP. (For additional information, 

refer to Appendix D for program monitoring and pages 61-64 for plan implementation and 

effectiveness monitoring in the RMP.) 

The RMP will be periodically evaluated to determine the effectiveness of the plan’s decisions 

and whether there are new issues or information that need to be considered. Adaptive 

management will also be applied as a continuous process of incorporating new and updated 

information, ensuring that the RMP remains flexible and responsive to changing conditions.

RMP amendments also may be necessary in the future when certain proposed actions or 

activities do not conform to the Socorro RMP.

VIII. Public Involvement and Cooperating Agencies

One of the BLM’s primary objectives during development of the Socorro RMP was to consider 

the views of various segments of the public by providing opportunities for meaningful 

participation throughout the planning process as required by FLPMA and NEPA regulations. 

During the initiation of the RMP process, the BLM’s interdisciplinary planning team conducted 

public scoping to identify issues relevant to the Socorro Field Office Planning Area. Due to the 

diverse scoping comments on off-highway vehicle (OHV) use, a separate workshop series on 

management of OHVs was conducted to investigate this issue more closely. 

A 90-day public review period on the Draft RMP/EIS commenced in April 2007. The BLM 

received approximately 109 comment submittals and conducted public meetings in May 2007.

The public commented on a number of topics including, but not limited to: rangeland resources, 

wilderness, recreational and historic trails, off-highway vehicle use, wilderness, climate change, 

and special designations. In response to these comments, some technical and editorial changes 

were made to the Proposed RMP/Final EIS. As required by regulations, the Proposed RMP/Final 

EIS was released to the public for a 30-day protest period and 60-day governor’s consistency 

review on December 5, 2009.

In addition to these public involvement opportunities, the Council of Environmental Quality’s 

(CEQ) regulations provide for and describe both lead and cooperating agency status, and 

emphasize agency cooperation early in the NEPA process (40 CFR 1501.6). In support of this 

mandate, the BLM invited local, State, and Federal agencies and tribes to participate as 

cooperating agencies with the BLM. Cooperating agency status offers the opportunity to assume 

additional roles and responsibilities beyond the collaborative planning process of attending 

public meetings and reviewing and commenting on plan documents. The Pueblo of Zuni and 

Catron County opted to participate as cooperating agencies throughout the planning process, and 
Socorro Resource Management Plan 6 Record of Decision

were responsible for reviewing draft materials and providing input during development of the 

alternatives. In addition, government agencies that elected to not participate as cooperating 

agencies were kept informed during the planning process and consultation continued with the 

other tribes. 

IX. Governor’s Consistency Review

The New Mexico Governor’s Office was provided a copy of the Proposed RMP/Final EIS for a 

60-day governor’s consistency review as required by BLM’s regulations [43 CFR, 1610.3-2(e)].

The BLM New Mexico received a letter from Governor Bill Richardson. The letter provided 

comments and recommended changes to the Socorro RMP regarding a state-designated 

conservation easement (CE) at Horse Springs Ranch and the levels of forage allocation for 

livestock and wildlife. 

The Governor’s letter stated that the BLM’s land tenure and fluid mineral decisions were

inconsistent with the purposes of the CE, which is to protect wildlife habitat. The BLM New 

Mexico State Director responded to the Governor, and provided several recommendations to 

address his comments in the Approved RMP, specifically in regards to the CE. In May 2009, 

Governor Richardson sent a letter to the State Director and concurred with the BLM’s 

recommendations to address the State’s CE. Based on BLM New Mexico’s response to the 

Governor further explaining the decision for forage allocation, no changes or modifications were 

made in the Approved RMP and therefore all consistency review issues were resolved.

In response to the state-designated CE, the BLM New Mexico State Director therefore modified 

Alternative B of the Proposed RMP/Final EIS by selecting the lands and realty decision in the 

No Action Alternative, which retains the BLM scattered parcels within the CE boundary (T3S 

R13W Section 29, T4S R13W Sections 5, 8, 17, and 18) rather than identify them for disposal.

This decision meets the habitat protection objectives of the State’s CE. With regard to the 

Governor’s concerns about the potential impacts that fluid mineral leasing decisions may have 

within the area of the CE, the State Director maintains the discretion to decline to issue leases on 

a case-by-case basis. In recognition of the particular resource concerns of this CE, the State 

Director will carefully exercise this discretion for any lease proposal in the surface area covered 

by the CE. After the issuance of this ROD, the BLM will undertake a plan amendment process to 

consider closing the area covered by the CE to fluid mineral leasing. (A legal description of the 

Horse Springs CE and affected Federal mineral estate for reference are provided in Appendix 1

of the ROD.)

X. Results of the Protest Review

BLM provided a 30-day protest period for the Proposed RMP/Final EIS (Proposed Plan) in 

accordance with 43 CFR 1610.5-2. The BLM received three protest letters. The protests were 

referred to the BLM Director for resolution and the identified issues involved three resource

areas: rangeland resources, wilderness and related route designations, and the Continental Divide 

National Scenic Trail (CDNST). Some of the protest issues included, but were not limited to: the 

consideration of a no grazing or reduced grazing alternative in the EIS; the adequacy of 

mitigating the effects of grazing on the aplomado falcon; adequate consideration of an alternative 

to protect lands with wilderness characteristics; whether the BLM’s 1980 inventory of lands with 

wilderness characteristic was current and consideration of new information; and the future 
Socorro Resource Management Plan 7 Record of Decision

alignment and protection of the CDNST. (For additional information on all of the protest issues 

and BLM responses, refer to the Socorro Resource Management Plan Protest Report at 

http://www.blm.gov.)

Following a review of the protests by the BLM Director, it was determined that the Socorro Field 

Office followed all applicable procedures, laws, regulations, and policies, and considered all 

relevant resource factors, as well as public input in developing the Socorro RMP. Therefore, the 

protests were dismissed. During the course of reviewing the protests, information came to the 

attention of the BLM that resulted in the modification of two decisions in the Approved RMP.

The first modification involves the CDNST. The second modification involves an area of BLM 

public land containing wilderness characteristics. In addition, some technical clarifications are 

identified in this ROD and/or were made in the Approved RMP in response to the protests.

Below is a summary of the technical clarifications and modifications.

RMP Technical Corrections/Clarifications

1) Explanation of Numbers of AUMs: Because of various New Mexico State land 

exchanges and consolidation of allotments, there is an appearance of an increase in the 

Animal Unit Months (AUMs), when in actuality there are none. Clarification regarding 

the number of AUMs due to changes in land tenure is provided in the RMP. (Refer to 

Appendix 2 in this ROD that explains the allotment consolidation and land exchange 

history affecting AUMs).

2) “I” and “M” Categories: There is one error in Appendix H (Table H-1, p. H-6) in the 

Proposed RMP/Final EIS. The table error shows allotment 1301 categorized as “I” which 

should be corrected to an “M” category. This correction is noted in the Approved RMP, 

and clarifies that because an allotment is categorized as an “I” does not imply it is in 

unsatisfactory condition. It may be in excellent condition, but has a resource conflict such 

as recreation that must be mitigated.

3) Clarification of RMP Level Decisions v. Plan Implementation Decisions for Travel 

Management: The cover letter in the Proposed RMP/Final EIS states that 

“. . . implementation decisions are not subject to protest under the BLM planning 

regulations, but are subject to an administrative review process.” This ROD explains the 

appeal process for the identification of the travel routes within designated areas for 

motorized vehicles, which is an implementation decision and is appealable. In addition, 

Appendix J, which identifies travel routes, is noted in the final RMP as an 

implementation decision.

4) Technical Error in Appendix J: The BLM acknowledges a technical error in Appendix J 

showing changes to ways in WSAs in the Proposed RMP/Final EIS, and has made the 

appropriate changes to the tables and maps in the Approved RMP.

RMP Modifications involving the CDNST and Lands with Wilderness Characteristics. 

1) Lands and Realty Decision for the Area Affecting the Continental Divide National Trail 

(CDNST): The BLM is committed to the continued and future establishment of the 

CDNST. In light of this issue, the Socorro RMP reflects a modified decision for Lands 
Socorro Resource Management Plan 8 Record of Decision

and Realty, Alternative B by adopting portions of Alternative C (Map 2-9) and the No 

Action Alternative (Map 3-17), lands suitable for disposal. This modified decision will 

provide more options in acquiring legal public rights-of-way for the CDNST between El 

Malpais NCA and the Cibola National Forest (Sawtooth Mountains Area) and west of Pie 

Town, NM. Specifically, the disposal area has been reduced in size to allow for 

acquisition of lands or easements for future CDNST routing and trail protection.

2) 600 Acres of BLM Public Land Adjacent to the U.S. Fish and Wildlife Service’s 

Chupadera Wilderness: As part of the protest resolution process, an additional review of 

the planning area was conducted to determine if wilderness characteristics were present.

Approximately 600 acres of BLM public land were found to contain wilderness 

characteristics because they adjoin the Chupadera Wilderness, which is managed by the 

U.S. Fish and Wildlife Service. The Socorro Proposed RMP/FEIS did not identify the 600 

acre area as including wilderness characteristics. Therefore, the BLM will select 

Alternative C for this area, which has a higher level of protection through a Lands and 

Realty decision. The BLM will issue this ROD and subsequently initiate a Resource 

Management Plan Amendment (RMPA) and supporting NEPA analysis to further address 

this area’s wilderness characteristics. The RMPA process will include opportunities for 

public participation.

XI. Availability of the Plan

Copies of the ROD and Socorro RMP are available by request from the following locations: The 

BLM Socorro Field Office, 901 S. Highway 85, Socorro, NM 87801, and on the Socorro Field 

Office web site at www.blm.gov/nm.

Approved

 8/20/10

Danita Burns, Socorro Field Office Manager Date

 8/20/10

Edwin Singleton, Albuquerque District Office Manager Date

 8/20/10

Linda S.C. Rundell, State Director Date
Socorro Resource Management Plan 9 Record of Decision

Appendix 1: Legal Description of Horse Springs Conservation 

Easement

This easement affects BLM NM’s Federal Subsurface Estate within the following legal 

description:

Horse Springs CE, Catron County, NM

T3S, R13W

Section 27: N1/2

Section 28: All

Section 32: S1/2NE1/4; NW1/4NE1/4

Section 33: NW1/4; NW1/4SW1/4; S1/2SW1/4

Section 34: N1/2

T4S, R13W

Section 3: N1/2; SE1/4

Section 4: N1/2

Section 5: Lots 1, 2, 3, 4; S1/2N1; SE1/4; N1/2SW1/4; SE1/4SW1/4

Section 8: All EXCEPT N1/2NE1/4; SW1/4SW1/4

Section 10: E1/2NE1/4

Section 11: W1/2

Section 17: W1/2SW1/4; E1/2W1/2; E1/2

Section 18: Lots 2, 3, 4; S1/2SE1/4; SE1/4SW1/4
Socorro Resource Management Plan 10 Record of Decision

Appendix 2: Explanatory Note: The History of AUMs and Related Land 

Acquisitions in the Socorro Field Office

Because of various New Mexico State land exchanges and consolidation of allotments, there is 

an appearance of an increase in the AUMs in the Socorro Field Office, when in actuality there 

are none. What appeared to be discrepancies in the number of AUMs is the result of changes in 

land tenure through BLM’s acquisition of New Mexico State land or consolidation of various 

allotments. The summary below denotes what changes have occurred. This explanation is also in 

the final Socorro RMP.

Consolidation of Allotments

The Monte Negro allotment was combined with the Canada Colorado and Canon Alamito 

allotments. In addition, there was an acquisition of state land to allow flexibility in grazing 

management. There was no change in the total livestock numbers allowed on the allotment. The 

carrying capacities of the allotments were 73 cattle year long (CYL), 47 CYL, and 61 CYL. The 

total number of cattle that are authorized on the Monte Negro Allotment is 181 CYL. The 

numbers of AUMs authorized on the individual allotments were 720 AUMs, 480 AUMs, and 720 

AUMs in the 1989 Socorro RMP equaling 1,920 AUMs. The Proposed RMP/Final EIS lists the 

number of AUMs at 1,929 AUMs. The difference of nine AUMs is due to a change of land 

tenure. The BLM acquired a portion of the state land within the allotment, thereby increasing the 

amount of public land and the number of AUMs by nine.

The total number of permitted livestock did not change, and remains at 181 CYL. After the 

consolidation and land exchange with the State of New Mexico, the authorized amount of cattle 

remained the same and the only change was the AUMs associated with the public and state land.

Land Tenure Adjustments

The following public land allotment acreage was adjusted as the result of New Mexico State 

Land exchanges: Black Mesa, Y-Ranch, Adobe Ranch, West Horse Mountain, and East Horse 

Mountain. The BLM increased its land base in allotments because of these exchanges. Although 

the public acreage and AUMs increased due to acquiring parcels of state land within the various 

allotments, the overall authorized number of livestock did not change. After the consolidation 

and land exchange with the State of New Mexico, the authorized amount of cattle remained the 

same. The only change was the number of AUMs associated with the public and state land.

Restored AUMs

The total number of AUMs for the Rio Grande allotment did not change from the original 

numbers. Some AUMs were held in suspension for the Rio Grande allotment and were 

consequently inactive for a period of time. These AUMs are now restored. As a result, there is no 

net gain in AUMs.