Exhibit 99(a)

Tax Return Guide

GREAT NORTHERN IRON ORE PROPERTIES
W-1290 First National Bank Building
332 Minnesota Street
Saint Paul, MN 55101-1361
(651) 224-2385
FAX (651) 224-2387

2005 TAX RETURN GUIDE

Dear Unit Holder:

This Tax Return Guide has been prepared to assist the certificate
holder in reporting the taxable income from Great Northern Iron Ore Properties (the Trust) as summarized on the
Substitute Form 1099-MISC (or Form 1042S for foreign investors) and the Trust Supplemental Statement. This information is being
mailed to all certificate holders shown on the record dates during 2005, as maintained by our transfer agent. If you use a
professional tax advisor, it is essential that they have this Guide to prepare your income tax return.

This Guide is merely intended to assist the investor in addressing many of
the issues that arise in reporting the Trust operations for federal and state income tax purposes. It is not intended to be
all-inclusive or to render specific professional tax advice. If you are a foreign investor, we recommend you consult your tax
advisor for proper income tax reporting due to the complexity of taxation of foreign investors. Should you have any questions
about the information in this Guide or need further assistance in income tax return preparation, please consult your tax advisor.

Street name holders may also use this Guide to calculate their
allocable share of Trust income and deductions if they know the number of units (shares) held on the record dates during the year.
Nominees and brokers should refer to the section in this Guide entitled Nominee Reporting Requirements which provides
guidance as to the preparation of Trust income tax information for their clients. Please contact the Trust office if you need a
bulk supply of these Guides.

Finally, please note that this Guide provides information for both domestic
and foreign investors. Certain sections in this Guide pertain only to a specific class of investors and are labeled as such.
Please read this Guide thoroughly and complete the worksheets carefully.

Sincerely yours and for the Trustees,

/s/   Joseph S. Micallef

---

January 2006

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page 2

TAX RETURN GUIDE

TABLE OF CONTENTS

|                                                                                                                           | Page
|-------------------------------------------------------------------------------------------------------------------------- | ----
|Tax Matters Relating to Great Northern Iron Ore Properties                                                                 |     
|General Information                                                                                                        |     
|Information for Foreign Investors                                                                                          |     
|Trust Income and Allocation                                                                                                |     
|Presentation of Tax Data                                                                                                   |     
|Classification of Trust Income                                                                                             |     
|Depletion                                                                                                                  |     
|Basis                                                                                                                      |     
|Certificate Amortization                                                                                                   |     
|Alternative Minimum Tax                                                                                                    |     
|State Taxation and Adjustments                                                                                             |     
|Backup Withholding                                                                                                         |     
|                                                                                                                          
|Instruction Outline                                                                                                        |     
|                                                                                                                          
|Worksheet A  Unit Holders that held a constant number of units on each of the four quarterly record dates during the year |     
|Schedule I         Individual Taxpayers                                                                                    |     
|Schedule II        Corporate Taxpayers                                                                                     |     
|                                                                                                                          
|Worksheet B  Unit Holders that purchased or sold units during the year                                                    |     
|Schedule I         Individual Taxpayers                                                                                    |     
|Schedule II        Corporate Taxpayers                                                                                     |     
|                                                                                                                          
|Worksheet C  Year End Basis and Certificate Amortization Computations                                                     |     
|                                                                                                                          
|Nominee Reporting Requirements                                                                                             |     
|                                                                                                                          
|Attachment for Income Tax Return to Reconcile Substitute Form 1099-MISC or Form 1042S for Certificate Holders of Record    |     
|Schedule for Individual Foreign Investors  Form 1042S                                                                     |     
|Schedule for Individual Domestic Investors  Substitute Form 1099-MISC                                                     |     

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TAX MATTERS RELATING TO GREAT NORTHERN IRON ORE PROPERTIES

General Information
Pursuant to an Election filed under Section 646 of the Tax Reform Act of 1986, as amended, the Trust is taxable as a grantor
trust for the years after 1988. As an investor in a grantor trust, you are required to report your proportionate share of the
Trusts taxable income on your federal and state income tax returns.

If you utilize professional assistance in preparing your income tax return,
it is essential that you provide your preparer with this Tax Return Guide, your Substitute Form 1099-MISC or Form 1042S (if
applicable) and your Trust Supplemental Statement (if applicable).

This Tax Return Guide is used to calculate the various components of
Trust income and deductions allocable to you. For the benefit of street name holders, this Guide is universal in that
if you know the number of shares (units) held on the record dates during the year, you can calculate the proper amount of Trust
income and deductions allocable to you, regardless of whether or not you received a Form 1099-MISC or Form 1042S from your broker.

This Guide is generally designed to instruct unit holders who utilize Form
1040  U.S. Individual Income Tax Return or Form 1120  U.S. Corporation Income Tax Return, which represents a vast
majority of our certificate holders. Foreign investors generally would utilize Form 1040NR  U.S. Nonresident Alien Income
Tax Return (Individuals) or Form 1120-F  U.S. Income Tax Return of a Foreign Corporation (Corporations). Please note that
the tax return line instructions within this Guide do not apply to foreign investors. Because the reporting of income or
deductions for foreign investors is dependent upon whether or not they are effectively connected with a United States trade or
business, we strongly recommend foreign investors consult with their tax advisors for proper income tax return preparation.

The Substitute Form 1099-MISC has been prepared only for domestic
certificate holders of record during the year (not street name holders). It is used to report the income allocable to
the domestic investor (as reported to the Internal Revenue Service and the Minnesota Department of Revenue), distributions
declared (not necessarily received within the year) and any taxes withheld. It should be emphasized that Box 1 on Substitute Form
1099-MISC contains distributions declared during the calendar year, not necessarily those actually received during the year. The
following table is provided to help clarify the timing differences:

|Distributions 
|--------------
|              
|Declared:     
|December 2004 
|March 2005    
|June 2005     
|September 2005
|December 2005 
|              

The distributions reported on Form 1099-MISC do not constitute
qualified dividend income as defined by the Jobs and Growth Tax Relief Reconciliation Act of 2003.

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page 4

(General Information  continued)

Regardless of when distributions were declared or paid, taxable income is
determined based upon your allocable share of the income of the Trust, not the distributions. Distributions need not normally be
reported anywhere on your income tax return. If you are a street name holder and received a Form 1099-DIV from
your broker, you should have the Form 1099-DIV voided and replaced with a Form 1099-MISC as prepared by the broker in
accordance with the Nominee Reporting Requirements section of this Guide. Should your broker not void the Form
1099-DIV, it is suggested you list the distributions reported by your broker on Schedule B, Part II of Form 1040 (Individuals) and
again as a negative amount (representing a nontaxable distribution) also on Schedule B, Part II of Form 1040 (Individuals), then
report your proportionate share of the Trusts income on your income tax return as computed by this Guide.

The Form 1042S has been prepared only for foreign certificate holders
of record during the year (not street name holders). It is used to report the income allocable to the foreign investor
(as reported to the Internal Revenue Service and the Minnesota Department of Revenue) and any taxes withheld. Regardless of
when distributions were declared or paid, taxable income is determined based upon your allocable share of the income of the Trust,
not the distributions. Distributions need not normally be reported anywhere on your income tax return.

The Trust Supplemental Statement shows only the shares (units) held on
the various record dates during the year. It accompanies the Substitute Form 1099-MISC or Form 1042S and may be helpful as a
reference in completing this Guide.

Information for Foreign Investors
Nonresident alien individuals or foreign corporations are generally subject to federal income tax at the rate of 30% (or lower
treaty rate) on certain items of gross income, including royalties, from sources within the United States. All of the income of
the Trust for this year was from sources within the United States. The income reported on Form 1042S includes interest income,
rental income and gain from the sale of domestic iron ore. The enclosed worksheets will assist you in the proper breakdown and
reporting of the income. The income tax withheld from your distributions is also shown on Form 1042S. You must file a United
States federal income tax return if the tax was underwithheld or to claim a refund for any overwithheld tax.

In general, if a nonresident alien individual or foreign corporation is
engaged in a trade or business in the United States and/or the nonresident alien individual or foreign corporation determines that
the Trust income is effectively connected with the conduct of a trade or business in the United States, then the Trust income is
taxable at the graduated tax rates applicable to individuals or corporations. Furthermore, a unit holder may elect to treat the
income (which constitutes income from real property) as effectively connected with the conduct of a trade or business in the
United States under Sections 871(d) or 882(d) of the Internal Revenue Code, or pursuant to any similar provisions of applicable
treaties. A unit holder whose Trust income is effectively connected with a United States trade or business or who elects to treat
it as such is entitled to claim a depletion deduction, to the extent allowed by law, and a certificate amortization deduction with
respect to such income. A United States federal income tax return must be filed to claim these deductions.

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(Information for Foreign Investors  continued)

A unit holder whose Trust income is effectively connected with a United
States trade or business, or who elects to treat it as such, is entitled to claim exemption from the 30% (or lower treaty rate)
withholding tax. Such exemption is claimed for a calendar year by filing, in duplicate, with the Trust, Form W-8ECI,
Certificate of Foreign Persons Claim for Exemption From Withholding on Income Effectively Connected With the Conduct
of a Trade or Business in the United States (or a substitute statement containing the information under Internal Revenue
Code Regulation Section 1.1441-4). The Form W-8ECI should be received by the Trust sufficiently in advance of the distribution to
which it is intended to apply. A separate Form W-8ECI (or substitute statement) must be filed with the Trust for each calendar
year in order to claim an exemption from withholding for that years income.

Under the Foreign Investment in Real Property Tax Act (FIRPTA), the units are
treated as United States real property interests. Thus, gain or loss from the sale or exchange of the units will be regarded as
arising from the sale or exchange of property effectively connected with the conduct of a United States trade or business.
Therefore, any sale of units during the year must be reported in the United States and the appropriate taxes paid, if any. The
gain or loss on the sale of a unit is calculated by deducting the adjusted basis of the unit from the unit selling price. The
format of Worksheet C may be used to calculate your adjusted basis. Include only those record dates before the sale date and
ignore the certificate amortization deduction calculation.

Because the taxation of foreign investors is a complex area, we recommend
you consult your tax advisor.

Trust Income and Allocation
The Trust determines and reports its taxable income on a calendar year basis utilizing the accrual method of accounting.
Shareholders (unit holders) of record at the end of each quarter are allocated a share of the Trusts quarterly income. There
were four equal income allocations during the year to holders of record as of the last business day of each calendar quarter. If
you are an investor with a taxable year other than a calendar year, you should report your share of income for those record dates
that coincide with your taxable year using Worksheet B.

Presentation of Tax Data
Worksheets are provided to assist the investor in calculating their allocable share of Trust income and deductions. You should
prepare either Worksheet A if you held the same number of units on each of the four quarterly record dates during the year
OR Worksheet B if you purchased or sold any units during the year. If you own units in several blocks or the number of
units which you own changed during the year, you need to reproduce the necessary copies of these worksheets and complete a
separate worksheet for each block of units acquired on a different date, at a different price or held for a different time period
in order to maintain your basis individually.

Classification of Trust Income
By a provision of the Internal Revenue Code, the iron ore royalty income earned by the Trust is treated as gain from the
sale or exchange of assets used in a trade or business under Code Section 1231, thereby qualifying for capital gain treatment.
With respect to the Tax Reform Act of 1986, the Trustees believe that the Trust does not engage in an activity which would be
considered a trade or business under the passive activity rules of the Internal Revenue Code. Accordingly, such income may not be
used to offset a unit holders losses from passive activities.

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page 6

Depletion
There was no income derived from ore properties having a cost basis during the year. Consequently, a cost depletion deduction
is not allowable.

A percentage depletion deduction is only allowable under Section 631 for any
tax year in which the capital gain tax rate equals or exceeds the maximum ordinary income tax rate. Accordingly, the percentage
depletion deduction is not available for individuals since the maximum ordinary income tax rate exceeds the capital gain tax rate.The percentage depletion deduction continues to remain available to domestic corporate taxpayers. It also remains available to
foreign corporate taxpayers if the income from the Trust is effectively connected with the conduct of a trade or business in the
United States or if you elect to treat the income as effectively connected. The corporate tax worksheets provide the factor to
calculate the percentage depletion deduction that is already reduced 20% as provided by Section 291.

Basis
Basis is increased by your allocable share of Trust income and is reduced by distributions and certificate amortization (if
any). Investors should use the format of Worksheet C to compute their year end basis annually. Basis should never be less than
zero. To the extent that distributions exceed your basis, the excess distribution should be treated as capital gain. Certificate
amortization would no longer be available. This computation Worksheet C is also included to assist the investor in computing gain
or loss upon the sale of any portion of the investors interest. If you sold some or all of your units prior to the end of
the year, you should use the format of Worksheet C to calculate your adjusted basis through the date of certificate disposition.
Do not calculate a certificate amortization deduction on any units disposed of during the year.

Certificate Amortization
Certificate holders were previously informed that amortizing the cost of Trust certificates is allowable beginning October 2,
1978, or date of purchase, whichever is later. Certificate amortization is a deduction for income tax purposes for domestic
investors if the certificates were held as of the end of the year. If you are a foreign investor and the income from the Trust is
effectively connected with the conduct of a trade or business in the United States or if you elect to treat the income as
effectively connected, you are also entitled to a certificate amortization deduction if the certificates were held as of the end
of the year. The certificate amortization deduction is not permitted for any person who holds a reversionary interest or is
related to, pursuant to Section 267, a person who holds a reversionary interest. Amortization of your interest should be
calculated based upon the number of days you owned the interest during the year in relation to the number of days until the Trust
will terminate on April 6, 2015. See Worksheet C for the suggested calculation formula to compute your certificate amortization,
if allowed. If you did not hold any units at the end of the year, ignore the certificate amortization deduction calculation.

Alternative Minimum Tax
For purposes of the Alternative Minimum Tax, the tax preference item for percentage depletion is only applicable to corporate
investors since no deduction is available to individuals. The entire corporate percentage depletion deduction is considered a tax
preference item and should be included on Form 4626  Alternative Minimum Tax-Corporations. Please follow the forms
instructions to determine if an additional tax liability is generated.

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page 7

State Taxation and Adjustments
Unit holders who meet Minnesotas minimum filing requirements will have to report their allocable share of the
Trusts income to the State of Minnesota. A Minnesota residents federal income will include their share of the
Trusts income. Nonresident unit holders will have to file a Minnesota income tax return to report Minnesota source income if
their total Minnesota source income, including their allocable share of the Trusts income, was at least $8,200 (minimum
threshold for a single taxpayer under age 65).

The Trustees have consistently taken the position that Minnesota will tax
income allocated to you provided you meet the minimum filing requirement. The state in which you are located, if other than
Minnesota, may also attempt to tax this income. Generally, if your state of residency taxes this income based on your residency,
that state may provide a credit for Minnesota taxes paid. Given the broad range of state tax implications, we strongly
recommend that you consult your tax advisor in order to determine the state tax implications of an allocation of income.

Individual taxpayers are allowed a subtraction for their allocable share of
the Trusts U.S. interest income on their Minnesota income tax return. Use the worksheets to calculate this amount and
include with any other subtractions on the Minnesota Individual Income Tax Return.

Corporate taxpayers are not allowed a percentage depletion deduction for
Minnesota. Therefore, the calculated percentage depletion deduction (if claimed on the federal return) must be shown as an
addition to Minnesota income.

If you are not required to file a Minnesota income tax return, you may ignore
the State of Minnesota Tax Return line reference numbers in the worksheets. However, to the extent that other states
have similar adjustments as explained above, the worksheets may be helpful in calculating these amounts. Many other states do
allow for the subtraction of U.S. interest income and, as stated above, also allow their residents a credit for taxes paid to
another state.

Backup Withholding
Federal income tax must be withheld at the rate of 28% by the payer if the payee fails to furnish his or her taxpayer
identification number (TIN) or if the payer is notified by the Internal Revenue Service that the payee has furnished an incorrect
TIN. A certificate holder will avoid backup withholding by furnishing his or her correct TIN to the Trusts disbursing agent:
Wells Fargo Bank, N.A., Shareowner Services, P.O. Box 64854, St. Paul, MN 55164-0854 (Telephone number: 1-800-468-9716).

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page 8

INSTRUCTION OUTLINE
Your Substitute Form 1099-MISC or Form 1042S (if applicable) provides your aggregate share of the Trusts taxable income
before deductions for the calendar year. For tax reporting purposes, the income should be separated into its various components.
If you are a street name holder and did not receive a Form 1099-MISC or Form 1042S, you should request such a form
from your broker (not Great Northern Iron Ore Properties); however this Guide can be used to calculate your allocable share of
income without having these forms if you know the number of shares held on the various record dates. The worksheets that follow
will assist you in completing your income tax return with respect to the Trusts income and deductions.

Please note that if you own units in several blocks or the number of units
which you own changed during the year, you need to reproduce the necessary copies of these worksheets and complete a separate
worksheet for each block of units acquired on a different date, at a different price or held for a different time period in order
to maintain your basis individually.

|STEP 1 |  | Before you begin, you will likely need a minimum of the following
federal income tax return forms:
|------ |  | --------------------------------------------------------------------------------------------------

| | Individual Domestic Investors
Form 1040  U.S. Individual Income Tax Return
Schedule B (Form 1040)  Interest and Ordinary Dividends
Schedule D (Form 1040)  Capital Gains and Losses
Schedule E (Form 1040)  Supplemental Income and Loss
Form 4797  Sales of Business Property
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | Corporate Domestic Investors
Form 1120  U.S. Corporation Income Tax Return
Schedule D (Form 1120)  Capital Gains and Losses
Form 4797  Sales of Business Property
Form 4626 Alternative Minimum Tax-Corporations
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | Individual Foreign Investors
Form 1040NR  U.S. Nonresident Alien Income Tax Return
| | -----------------------------------------------------------------------------------

| | Corporate Foreign Investors
Form 1120-F  U.S. Income Tax Return of a Foreign Corporation
| | -----------------------------------------------------------------------------------------

| | Various state income tax return forms may also be required
depending on the investors tax status and domicile.
| | ---------------------------------------------------------------------------------------------------------------

|STEP 2 |  | Determine which worksheet to use. Investors who held a constant
number of units on each of the four quarterly record dates during the year should use Worksheet A. All others should use
Worksheet B.
|------ |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|STEP 3 |  | Complete Worksheet A or B (but not both). The Trust
Supplemental Statement received (if applicable) will provide the shares (units) held on the various record dates during the year.
The worksheet is designed to reconcile to your Substitute Form 1099-MISC or Form 1042S for calendar year taxpayers of record.
|------ |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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page 9

(INSTRUCTION OUTLINE  continued)

|STEP 4 |  | If you held units of interest at the end of the year, complete
Worksheet C. If you did not hold units of interest at the end of the year, you need not complete Worksheet C as your basis should
be zero and the certificate amortization deduction calculation is irrelevant. However, you may wish to use the format of Worksheet
C to calculate your basis through the date of certificate disposition.
|------ |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|STEP 5 |  | If you are a domestic investor, enter the amounts calculated on
Worksheet A or Worksheet B onto the appropriate income tax return lines as indicated on the worksheets. If you are a foreign
investor, reporting of the calculated amounts is dependent upon whether the income is effectively or not effectively connected
with a United States trade or business. As this determination is dependent upon your specific activities in the United States, we
recommend you consult your tax advisor for proper reporting before entering the amounts calculated on Worksheet A or Worksheet B
onto your income tax return.
|------ |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|STEP 6 |  | Individual domestic investors of record should complete
Schedule S-D with the amounts calculated from Worksheet A or Worksheet B (lines 1, 2 & 3). This schedule
provides a reconciliation of the reported income to Substitute Form 1099-MISC (which was sent to the Internal Revenue Service and
the Minnesota Department of Revenue).
|------ |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | Individual foreign investors of record should complete Schedule
S-F with the amounts calculated from Worksheet A or Worksheet B (lines 1, 2 & 3). This schedule provides a reconciliation of
the reported income to Form 1042S (which was sent to the Internal Revenue Service and the Minnesota Department of Revenue).
Foreign investors must also indicate where the income was listed on their income tax return as determined in Step 5 above.
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|STEP 7 |  | Certificate holders of record should attach either Schedule S-D or
S-F, as appropriate, to your income tax return.
|------ |  | ------------------------------------------------------------------------------------------------------------------

|STEP 8 |  | Retain this Guide, Substitute Form 1099-MISC or Form 1042S (if
applicable) and the Trust Supplemental Statement (if applicable) with your permanent records as it contains basis and other
important information which may be needed in future years.
|------ |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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# WORKSHEET A

# CALCULATION OF TAXABLE INCOME FOR UNIT HOLDERS THAT HELD A CONSTANT NUMBER OF UNITS
ON EACH OF THE FOUR QUARTERLY RECORD DATES DURING THE YEAR

*Please note that the income tax return lines referenced below pertain only to domestic investors.
If you are a foreign investor, the reporting of this income is dependent upon whether the income
is effectively or not effectively connected with a United States trade or business. As this determination is
dependent upon your specific activities in the United States, we recommend you consult your tax advisor
for the proper reporting of this income before entering the amounts calculated onto your income
tax return Form 1040NR (Individuals) or Form 1120-F (Corporations).

# SCHEDULE I:    INDIVIDUAL TAXPAYERS:          YEAR:    2005

|                                                                                                                          |  |           | 
|------------------------------------------------------------------------------------------------------------------------- |  | --------- | 
|                                                                                                                          |  |           | 
|                                                                                                                         
|1)  Interest Income                                                                                                       |  | 0.168024  | 
|                                                                                                                          |  |           | 
|2)  Rental Income                                                                                                         |  | 0.073816  | 
|                                                                                                                          |  |           | 
|3)  Gain from Sale of Iron      Ore, Section 1231                                                                         |  | 10.329828 | 
|                                                                                                                          |  |           | 
|Record Holders Proof Reconciliation:                                                                                     
|Sum of lines 1, 2 & 3 should equal
            Substitute Form 1099-MISC Box 2
            or Form 1042S (if applicable): |  |           | 
|                                                                                                                          |  |           | 
|4)  Certificate Amortization Deduction      as calculated from Worksheet C:                                               |  |           | 
|                                                                                                                          |  |           | 
|STATE TAX ADJUSTMENT:    Subtract U.S. Interest                                                                           |  | 0.155860  | 
|                                                                                                                          |  |           | 

SCHEDULE II:    CORPORATE TAXPAYERS:

|                                                                                                                          |  |           | 
|------------------------------------------------------------------------------------------------------------------------- |  | --------- | 
|                                                                                                                          |  |           | 
|                                                                                                                         
|1)  Interest Income                                                                                                       |  | 0.168024  | 
|                                                                                                                          |  |           | 
|2)  Rental Income                                                                                                         |  | 0.073816  | 
|                                                                                                                          |  |           | 
|3)  Gain from Sale of Iron      Ore, Section 1231                                                                         |  | 10.329828 | 
|                                                                                                                          |  |           | 
|Record Holders Proof Reconciliation:                                                                                     
|Sum of lines 1, 2 & 3 should equal
            Substitute Form 1099-MISC Box 2
            or Form 1042S (if applicable): |  |           | 
|                                                                                                                          |  |           | 
|4)  Percentage Depletion Deduction                                                                                        |  | 1.439876  | 
|                                                                                                                          |  |           | 
|5)  AMT Preference Item:      Percentage Depletion                                                                        |  | 1.439876  | 
|                                                                                                                          |  |           | 
|6)  Certificate Amortization Deduction      as calculated from Worksheet C:                                               |  |           | 
|                                                                                                                          |  |           | 
|STATE TAX ADJUSTMENT:    Add Percentage Depletion                                                                         |  | 1.439876  | 
|                                                                                                                          |  |           | 

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page 11

# WORKSHEET B

# CALCULATION OF TAXABLE INCOME FOR UNIT HOLDERS
THAT PURCHASED OR SOLD UNITS DURING THE YEAR

*Please note that the income tax return lines referenced below pertain only to domestic investors.
If you are a foreign investor, the reporting of this income is dependent upon whether the income
is effectively or not effectively connected with a United States trade or business. As this determination is
dependent upon your specific activities in the United States, we recommend you consult your tax advisor
for the proper reporting of this income before entering the amounts calculated onto your income
tax return Form 1040NR (Individuals) or Form 1120-F (Corporations).

# SCHEDULE I:    INDIVIDUAL TAXPAYERS:          YEAR:    2005

First Quarter  March 31, 2005

|                                                  |  |          | 
|------------------------------------------------- |  | -------- | 
|                                                  |  |          | 
|                                                 
|1)  Interest Income                               |  | 0.042006 | 
|                                                  |  |          | 
|2)  Rental Income                                 |  | 0.018454 | 
|                                                  |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231 |  | 2.582457 | 
|                                                  |  |          | 
|STATE TAX ADJUSTMENT:    Subtract U.S. Interest   |  | 0.038965 | 
|                                                  |  |          | 

Second Quarter  June 30, 2005

|                                                  |  |          | 
|------------------------------------------------- |  | -------- | 
|                                                  |  |          | 
|                                                 
|1)  Interest Income                               |  | 0.042006 | 
|                                                  |  |          | 
|2)  Rental Income                                 |  | 0.018454 | 
|                                                  |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231 |  | 2.582457 | 
|                                                  |  |          | 
|STATE TAX ADJUSTMENT:    Subtract U.S. Interest   |  | 0.038965 | 
|                                                  |  |          | 

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page 12

(Individual continued)
Third Quarter  September 30, 2005

|                                                  |  |          | 
|------------------------------------------------- |  | -------- | 
|                                                  |  |          | 
|                                                 
|1)  Interest Income                               |  | 0.042006 | 
|                                                  |  |          | 
|2)  Rental Income                                 |  | 0.018454 | 
|                                                  |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231 |  | 2.582457 | 
|                                                  |  |          | 
|STATE TAX ADJUSTMENT:    Subtract U.S. Interest   |  | 0.038965 | 
|                                                  |  |          | 

Fourth Quarter  December 30, 2005

|                                                  |  |          | 
|------------------------------------------------- |  | -------- | 
|                                                  |  |          | 
|                                                 
|1)  Interest Income                               |  | 0.042006 | 
|                                                  |  |          | 
|2)  Rental Income                                 |  | 0.018454 | 
|                                                  |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231 |  | 2.582457 | 
|                                                  |  |          | 
|STATE TAX ADJUSTMENT:    Subtract U.S. Interest   |  | 0.038965 | 
|                                                  |  |          | 

GRAND TOTAL RECONCILIATION OF ABOVE RECORD DATES FOR
    WORKSHEET B (Sum of respective total lines above):

|                                                                                                             |  |   | 
|------------------------------------------------------------------------------------------------------------ |  | - | 
|                                                                                                             |  |   | 
|                                                                                                            
|1)  Interest Income                                                                                          |  |   | 
|                                                                                                             |  |   | 
|2)  Rental Income                                                                                            |  |   | 
|                                                                                                             |  |   | 
|3)  Gain from Sale of Iron      Ore, Section 1231                                                            |  |   | 
|                                                                                                             |  |   | 
|Record Holders Proof Reconciliation:                                                                        
|Sum of lines 1, 2 & 3 should equal Substitute Form 1099-MISC Box 2
            or Form 1042S (if applicable) |  | $ | 
|                                                                                                             |  |   | 
|4)  Certificate Amortization Deduction      as calculated from Worksheet C:                                  |  |   | 
|                                                                                                             |  |   | 
|STATE TAX ADJUSTMENT:    Subtract U.S. Interest                                                              |  |   | 
|                                                                                                             |  |   | 

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page 13

# SCHEDULE II:    CORPORATE TAXPAYERS:          YEAR:    2005

First Quarter  March 31, 2005

|                                                   |  |          | 
|-------------------------------------------------- |  | -------- | 
|                                                   |  |          | 
|                                                  
|1)  Interest Income                                |  | 0.042006 | 
|                                                   |  |          | 
|2)  Rental Income                                  |  | 0.018454 | 
|                                                   |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231  |  | 2.582457 | 
|                                                   |  |          | 
|4)  Percentage Depletion Deduction                 |  | 0.359969 | 
|                                                   |  |          | 
|5)  AMT Preference Item:      Percentage Depletion |  | 0.359969 | 
|                                                   |  |          | 
|STATE TAX ADJUSTMENT:    Add Percentage Depletion  |  | 0.359969 | 
|                                                   |  |          | 

Second Quarter  June 30, 2005

|                                                   |  |          | 
|-------------------------------------------------- |  | -------- | 
|                                                   |  |          | 
|                                                  
|1)  Interest Income                                |  | 0.042006 | 
|                                                   |  |          | 
|2)  Rental Income                                  |  | 0.018454 | 
|                                                   |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231  |  | 2.582457 | 
|                                                   |  |          | 
|4)  Percentage Depletion Deduction                 |  | 0.359969 | 
|                                                   |  |          | 
|5)  AMT Preference Item:      Percentage Depletion |  | 0.359969 | 
|                                                   |  |          | 
|STATE TAX ADJUSTMENT:    Add Percentage Depletion  |  | 0.359969 | 
|                                                   |  |          | 

---

page 14

(Corporate continued)
Third Quarter  September 30, 2005

|                                                   |  |          | 
|-------------------------------------------------- |  | -------- | 
|                                                   |  |          | 
|                                                  
|1)  Interest Income                                |  | 0.042006 | 
|                                                   |  |          | 
|2)  Rental Income                                  |  | 0.018454 | 
|                                                   |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231  |  | 2.582457 | 
|                                                   |  |          | 
|4)  Percentage Depletion Deduction                 |  | 0.359969 | 
|                                                   |  |          | 
|5)  AMT Preference Item:      Percentage Depletion |  | 0.359969 | 
|                                                   |  |          | 
|STATE TAX ADJUSTMENT:    Add Percentage Depletion  |  | 0.359969 | 
|                                                   |  |          | 

Fourth Quarter - December 30, 2005

|                                                   |  |          | 
|-------------------------------------------------- |  | -------- | 
|                                                   |  |          | 
|                                                  
|1)  Interest Income                                |  | 0.042006 | 
|                                                   |  |          | 
|2)  Rental Income                                  |  | 0.018454 | 
|                                                   |  |          | 
|3)  Gain from Sale of Iron      Ore, Section 1231  |  | 2.582457 | 
|                                                   |  |          | 
|4)  Percentage Depletion Deduction                 |  | 0.359969 | 
|                                                   |  |          | 
|5)  AMT Preference Item:      Percentage Depletion |  | 0.359969 | 
|                                                   |  |          | 
|STATE TAX ADJUSTMENT:    Add Percentage Depletion  |  | 0.359969 | 
|                                                   |  |          | 

GRAND TOTAL RECONCILIATION OF ABOVE RECORD DATES FOR
    WORKSHEET B (Sum of respective total lines above):

|                                                                                                             |  |   | 
|------------------------------------------------------------------------------------------------------------ |  | - | 
|                                                                                                             |  |   | 
|                                                                                                            
|1)  Interest Income                                                                                          |  |   | 
|                                                                                                             |  |   | 
|2)  Rental Income                                                                                            |  |   | 
|                                                                                                             |  |   | 
|3)  Gain from Sale of Iron      Ore, Section 1231                                                            |  |   | 
|                                                                                                             |  |   | 
|Record Holders Proof Reconciliation:                                                                        
|Sum of lines 1, 2 & 3 should equal Substitute Form 1099-MISC Box 2
            or Form 1042S (if applicable) |  | $ | 
|                                                                                                             |  |   | 
|4)  Percentage Depletion Deduction                                                                           |  |   | 
|                                                                                                             |  |   | 
|5)  AMT Preference Item: Percentage Depletion                                                                |  | $ | 
|                                                                                                             |  |   | 
|6)  Certificate Amortization Deduction from Worksheet C                                                      |  | $ | 
|                                                                                                             |  |   | 
|STATE TAX ADJUSTMENT:    Add Percentage Depletion                                                            |  |   | 
|                                                                                                             |  |   | 

---

page 15

# WORKSHEET C

# YEAR END BASIS AND CERTIFICATE AMORTIZATION COMPUTATIONS

Please note that a separate worksheet must be maintained for each unit or block of units
purchased on a particular date in order to accurately compute the basis in such units.

|                                                                                                                                                                                                             |  |                        | 
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |  | ---------------------- | 
|                                                                                                                                                                                                             |  |                        | 
|                                                                                                                                                                                                            
|Basis: Beginning of the year ordate of purchase, as applicable                                                                                                                                               |  | $                      | 
|                                                                                                                                                                                                             |  |                        | 
|Plus: Income (Sum of Interest Income, Rental Income & Section 1231 Gain)                                                                                                                                     |  | $                      | 
|                                                                                                                                                                                                             |  |                        | 
|Less: Distributions received pertaining to                                                                                                                                                                 
|First Quarter  March 31, 2005                                                                                                                                                                               |  | 2.20                   | 
|                                                                                                                                                                                                             |  |                        | 
|Second Quarter  June 30, 2005                                                                                                                                                                               |  | 2.40                   | 
|                                                                                                                                                                                                             |  |                        | 
|Third Quarter  September 30, 2005                                                                                                                                                                           |  | 2.80                   | 
|                                                                                                                                                                                                             |  |                        | 
|Fourth Quarter  December 30, 2005                                                                                                                                                                           |  | 3.00                   | 
|                                                                                                                                                                                                             |  |                        | 
|Subtotal:  (Beginning Basis plus Income less Distributions)                                                                                                                                                  |  | $                      | 
|                                                                                                                                                                                                             | 
|Certificate Amortization Deduction Calculation,
  if you held your shares as of year end (Note: Use only
  one calculation below for each unit or block of units
  to determine your deduction, if allowed):
|                                                                                                                                                                                                            
|If you owned shares for the entire year and held them
  as of year-end, use this Annual Rate:                                                                                                                |  | 0.097385              
|                                                                                                                                                                                                             | 
|OR                                                                                                                                                                                                          
|If you purchased shares during the year and held them
as of year-end, compute your Partial Rate as follows:                                                                                                 
|Number of Days shares were    owned during the year:                                                                                                                                                         |  | (a)                   
|                                                                                                                                                                                                             | 
|Number of Days remaining to    the Trust as of end of the year:                                                                                                                                              |  | (b)   3383            
|                                                                                                                                                                                                             | 
|Total Number of Days to amortize    certificate [Add (a) + (b)]:                                                                                                                                             |  | (c)                   
|                                                                                                                                                                                                             | 
|Partial Rate equals (a) divided by (c):                                                                                                                                                                     
|                                                                                                                                                                                                             | 
|Applicable Certificate Amortization % Rate (either Annual or Partial Rate from above):                                                                                                                       |  | X                      | 
|                                                                                                                                                                                                             | 
|Certificate Amortization Deduction (Subtotal times Cert. Amort. Rate):                                                                                                                                       |  | =                      | 
|                                                                                                                                                                                                             | 
|Adjusted Basis at year end (Subtotal less Certificate Amortization Deduction):                                                                                                                               |  |                        | 
|                                                                                                                                                                                                             | 
|Units (Shares) held at year end:         2005                                                                                                                                                                |  | (needed for next year)
|                                                                                                                                                                                                             | 
|Adjusted Basis per Unit (Share) at year end (Adjusted Basis divided by Units):                                                                                                                               |  |                        | 
|                                                                                                                                                                                                             | 

---

page 16

# NOMINEE REPORTING REQUIREMENTS:         YEAR:    2005

If your federal ID number is shown on Form 1099-MISC or Form 1042S, and two
or more recipients are shown or the form includes amounts belonging to another person, you are considered a nominee recipient. You
must file Form 1099-MISC or Form 1042S, as appropriate, for each of the other owners showing the income allocable to each. File
Form(s) 1099-MISC with Form 1096 (Annual Summary and Transmittal of U.S. Information Returns) at the Internal Revenue Service
Center for your area. On Forms 1099-MISC and 1042S, you should be listed as the payer and the other owner(s) should be listed as
the recipient. A husband or wife is not required to file a nominee return to show payments for the other. To prepare a Form
1099-MISC or Form 1042S for each recipient, you must know the number of units (shares) held by the recipient on each of the
Trust's four record dates. The record dates and income factors needed to calculate income allocable to each recipient are listed
below. You should multiply the units held on each record date times the applicable income factor, adding the results together and
reporting the grand total on Form 1099-MISC Box 2 or Form 1042S to each recipient. When completed, all income in the
Nominees Form 1099-MISC or Form 1042S should be accounted for and each recipient should receive a Form 1099-MISC or Form
1042S, a copy of this Guide and a summary of the recipients holdings on each of the record dates below. These same
instructions apply to brokerage firms as to their preparation of a Form 1099-MISC or Form 1042S for their clients holding
interests in the Trust in street name.

|RECORD DATES:                      |  | INCOME FACTORS: |  | TAXPAYER ID NUMBER:
|---------------------------------- |  | --------------- |  | -------------------
|First Quarter  March 31, 2005     |  |                 |  | 2.642917           
|Second Quarter  June 30, 2005     |  |                 |  | 2.642917           
|Third Quarter  September 30, 2005 |  |                 |  | 2.642917           
|Fourth Quarter  December 30, 2005 |  |                 |  | 2.642917           
|                                   |  |                
|                                   |  |                 |  | 10.571668          
|                                   |  |                

---

S-F

NAME_________________________________   SOCIAL SECURITY #________________________________

Attachment  Schedule Reconciling Form 1042S to Individual Income Tax Return
for Certificate Holders of Record

|                  
|------------------
|                  
|1)                
|                  
|2)                
|                  
|3)                
|                  
|                  
|EQUALS: Form 1042S
|                  

GREAT NORTHERN IRON ORE PROPERTIES

---

S-D

NAME_________________________________   SOCIAL SECURITY #________________________________

Attachment  Schedule Reconciling Substitute Form 1099-MISC to Individual Income Tax Return
for Certificate Holders of Record

|                                                          
|----------------------------------------------------------
|                                                          
|1)                                                        
|                                                          
|2)                                                        
|                                                          
|3)                                                        
|                                                          
|                                                          
|EQUALS:  Substitute Form                   1099-MISC Box 2
|                                                          

GREAT NORTHERN IRON ORE PROPERTIES

---