1.    Basis of Presentation

Nature of Business

Natural Resource Partners L.P. (the "Partnership") engages principally in the business of owning, managing and leasing a diversified portfolio of mineral properties in the United States, including interests in coal and other natural resources and owns a non-controlling  i 49% interest in Sisecam Wyoming LLC ("Sisecam Wyoming"), a trona ore mining and soda ash production business. The Partnership is organized into two operating segments further described in Note 6. Segment Information. The Partnership’s operations are conducted through, and its operating assets are owned by, its subsidiaries. The Partnership owns its subsidiaries through  i one wholly owned operating company, NRP (Operating) LLC ("Opco"). As used in these Notes to Consolidated Financial Statements, the terms "NRP," "we," "us" and "our" refer to Natural Resource Partners L.P. and its subsidiaries, unless otherwise stated or indicated by context.

Principles of Consolidation and Reporting

The accompanying unaudited Consolidated Financial Statements of the Partnership have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") for interim financial information and with Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. These financial statements should be read in conjunction with the financial statements for the year ended December 31, 2022 and notes thereto included in the Partnership's Annual Report on Form 10-K, which was filed with the SEC on March 3, 2023. 

Recently Adopted Accounting Standard

On January 1, 2023, NRP adopted Accounting Standards Update ("ASU") 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06)”. The ASU includes targeted improvements to earnings per share, which the Partnership adopted on a modified retrospective basis. The adoption of this ASU did not have a material impact on the Partnership’s Consolidated Financial Statements. See Note 5. Net Income Per Common Unit for the calculations of our basic and diluted net income per common unit. See Note 3. Class A Convertible Preferred Units and Warrants for disclosures related to our convertible preferred units and warrants.

2.    Revenues from Contracts with Customers

The following table presents the Partnership's Mineral Rights segment revenues by major source:

The following table details the Partnership's Mineral Rights segment receivables and liabilities resulting from contracts with customers:

The following table shows the activity related to the Partnership's Mineral Rights segment deferred revenue: 

The Partnership's non-cancelable annual minimum payments due under the lease terms of its coal and aggregates royalty leases are as follows as of  March 31, 2023 (in thousands): 

3.      Class A Convertible Preferred Units and Warrants

On March 2, 2017, NRP issued $ i 250 million of Class A Convertible Preferred Units representing limited partner interests in NRP (the "preferred units") to certain entities controlled by funds affiliated with The Blackstone Group Inc. (collectively referred to as "Blackstone") and certain affiliates of GoldenTree Asset Management LP (collectively referred to as "GoldenTree") (together the "preferred purchasers") pursuant to a Preferred Unit and Warrant Purchase Agreement. NRP issued  i 250,000 preferred units to the preferred purchasers at a price of $ i 1,000 per preferred unit (the "per unit purchase price"), less a  i 2.5% structuring and origination fee. The preferred units entitle the preferred purchasers to receive cumulative distributions at a rate of  i 12% of the purchase price per year, up to one half of which NRP may pay in additional preferred units (such additional preferred units, the "PIK units"). The preferred units have a perpetual term, unless converted or redeemed as described below.

NRP also issued two tranches of warrants (the "warrants") to purchase common units to the preferred purchasers (warrants to purchase  i 1.75 million common units with a strike price of $ i 22.81 and warrants to purchase  i 2.25 million common units with a strike price of $ i 34.00). The warrants may be exercised by the holders thereof at any time before the eighth anniversary of the closing date. Upon exercise of the warrants, NRP may, at its option, elect to settle the warrants in common units or cash, each on a net basis.

After March 2, 2022 and prior to March 2, 2025, the holders of the preferred units may elect to convert up to  i 33% of the outstanding preferred units in any 12-month period into common units if the volume weighted average trading price of our common units (the "VWAP") for the 30 trading days immediately prior to date notice is provided is greater than $ i 51.00. In such case, the number of common units to be issued upon conversion would be equal to the per unit purchase price plus the value of any accrued and unpaid distributions divided by an amount equal to a  i 7.5% discount to the VWAP for the 30 trading days immediately prior to the notice of conversion. Rather than have the preferred units convert to common units in accordance with the provisions of this paragraph, NRP would have the option to elect to redeem the preferred units proposed to be converted for cash at a price equal to the per unit purchase price plus the value of any accrued and unpaid distributions.

On or after March 2, 2025, the holders of the preferred units may elect to convert the preferred units to common units at a conversion rate equal to the Liquidation Value divided by an amount equal to a  i 10% discount to the VWAP for the 30 trading days immediately prior to the notice of conversion. The “liquidation value” will be an amount equal to the greater of: (1) (a) the per unit purchase price multiplied by (i) prior to March 2, 2020,  i 1.50, (ii) on or after March 2, 2020 and prior to March 2, 2021,  i 1.70 and (iii) on or after March 2, 2021,  i 1.85, less (b)(i) all preferred unit distributions previously made by NRP and (ii) all cash payments previously made in respect of redemption of any PIK units; and (2) the per unit purchase price plus the value of all accrued and unpaid distributions.

To the extent the holders of the preferred units have not elected to convert their preferred units before March 2, 2029, NRP has the right to force conversion of the preferred units at a price equal to the liquidation value divided by an amount equal to a  i 10% discount to the VWAP for the 30 trading days immediately prior to the notice of conversion.

In addition, NRP has the ability to redeem at any time (subject to compliance with its debt agreements) all or any portion of the preferred units and any outstanding PIK units for cash. The redemption price for each outstanding PIK unit is $ i 1,000 plus the value of any accrued and unpaid distributions per PIK unit. The redemption price for each preferred unit is the liquidation value divided by the number of outstanding preferred units. The preferred units are redeemable at the option of the preferred purchasers only upon a change in control.

The terms of the preferred units contain certain restrictions on NRP's ability to pay distributions on its common units. To the extent that either (i) NRP's consolidated Leverage Ratio, as defined in the Partnership's Fifth Amended and Restated Partnership Agreement dated March 2, 2017 (the "restated partnership agreement"), is greater than 3.25x, or (ii) the ratio of NRP's Distributable Cash Flow (as defined in the Restated Partnership Agreement) to cash distributions made or proposed to be made is less than 1.2x (in each case, with respect to the most recently completed four-quarter period), NRP may not increase the quarterly distribution above $ i 0.45 per quarter without the approval of the holders of a majority of the outstanding preferred units. In addition, if at any time after January 1, 2022, any PIK units are outstanding, NRP may not make distributions on its common units until it has redeemed all PIK units for cash.

The holders of the preferred units have the right to vote with holders of NRP’s common units on an as-converted basis and have other customary approval rights with respect to changes of the terms of the preferred units. In addition, Blackstone has certain approval rights over certain matters as identified in the restated partnership agreement. GoldenTree also has more limited approval rights that will expand once Blackstone's ownership goes below the minimum preferred unit threshold (as defined below). These approval rights are not transferrable without NRP's consent. In addition, the approval rights held by Blackstone and GoldenTree will terminate at such time that Blackstone (together with their affiliates) or GoldenTree (together with their affiliates), as applicable, no longer own at least  i 20% of the total number of preferred units issued on the closing date, together with all PIK units that have been issued but not redeemed (the "minimum preferred unit threshold").

At the closing, pursuant to the Board Representation and Observation Rights Agreement, the Preferred Purchasers received certain board appointment and observation rights, and Blackstone appointed one director and one observer to the Board of Directors.

NRP also entered into a registration rights agreement (the "preferred unit and warrant registration rights agreement") with the preferred purchasers, pursuant to which NRP is required to file (i) a shelf registration statement to register the common units issuable upon exercise of the warrants and to cause such registration statement to become effective not later than 90 days following the closing date and (ii) a shelf registration statement to register the common units issuable upon conversion of the preferred units and to cause such registration statement to become effective not later than the earlier of the fifth anniversary of the closing date or 90 days following the first issuance of any common units upon conversion of preferred units (the "registration deadlines"). In addition, the preferred unit and warrant registration rights agreement gives the preferred purchasers piggyback registration and demand underwritten offering rights under certain circumstances. The shelf registration statement to register the common units issuable upon exercise of the warrants became effective on April 20, 2017. If the shelf registration statement to register the common units issuable upon conversion of the preferred units is not effective by the applicable registration deadline, NRP will be required to pay the preferred purchasers liquidated damages in the amounts and upon the term set forth in the preferred unit and warrant registration rights agreement.

Accounting for the Preferred Units and Warrants

Classification

The preferred units are accounted for as temporary equity on NRP's Consolidated Balance Sheets due to certain contingent redemption rights that may be exercised at the election of preferred purchasers. The warrants are accounted for as equity on NRP's Consolidated Balance Sheets.

Initial Measurement

The net transaction price was allocated to the preferred units and warrants based on their relative fair values at inception date. NRP allocated the transaction issuance costs to the preferred units and warrants primarily on a pro-rata basis based on their relative inception date allocated values.

Subsequent Measurement

Preferred Units

Subsequent adjustment of the preferred units will not occur until NRP has determined that the conversion or redemption of all or a portion of the preferred units is probable of occurring. Once conversion or redemption becomes probable of occurring, the carrying amount of the preferred units will be accreted to their redemption value over the period from the date the feature is probable of occurring to the date the preferred units can first be converted or redeemed. 

In  February 2023, the Partnership received a notice from holders of the Class A Preferred Units exercising their right to either convert or redeem, at the election of NRP, an aggregate of  i 47,499 Class A Preferred Units. The Partnership chose to redeem the preferred units for $ i 47.5 million in cash rather than issuing common units. Of the originally issued  i 250,000 Class A Preferred Units,  i 202,501 Class A Preferred Units remain outstanding as of March 31, 2023.

Activity related to the preferred units is as follows:

Warrants

As of March 31, 2023 and December 31, 2022 there were  i 3.0 million warrants outstanding, which included warrants to purchase  i 0.75 million common units at a strike price of $ i 22.81 and warrants to purchase  i 2.25 million common units with a strike price of $ i 34.00. These warrants had a $ i 48.0 million carrying value included in warrant holders' interest within partners' capital on the Partnership's Consolidated Balance Sheets at March 31, 2023 and December 31, 2022. Subsequent adjustment of the warrants will not occur until the warrants are exercised, at which time, NRP may, at its option, elect to settle the warrants in common units or cash, each on a net basis. The net basis will be equal to the difference between the Partnership's common unit price and the strike price of the warrant. Once warrant exercise occurs, the difference between the carrying amount of the warrants and the net settlement amount will be allocated on a pro-rata basis to the common unitholders and general partner.

Embedded Features

Certain embedded features within the preferred unit and warrant purchase agreement are accounted for at fair value and are remeasured each quarter. See Note 10. Fair Value Measurements for further information regarding valuation of these embedded derivatives.

4.    Common and Preferred Unit Distributions

The Partnership makes cash distributions to common and preferred unitholders on a quarterly basis, subject to approval by the Board of Directors of GP Natural Resource Partners LLC (the "Board of Directors"). NRP recognizes both common unit and preferred unit distributions on the date the distribution is declared.

Distributions made on the common units and the general partner's general partner ("GP") interest are made on a pro-rata basis in accordance with their relative percentage interests in the Partnership. The general partner is entitled to receive  i 2% of such distributions.

Income available to common unitholders and the general partner is reduced by preferred unit distributions that accumulated during the period. NRP reduced net income available to common unitholders and the general partner by $ i 6.7 million and $ i 7.5 million during the three months ended March 31, 2023 and 2022, respectively, as a result of accumulated preferred unit distributions earned during the period. Of the $ i 6.7 million in accumulated preferred unit distributions earned during March 31, 2023, $ i 0.6 million was paid in February 2023 in connection with the preferred units that were redeemed. Income available to common unitholders and the general partner is also reduced by the difference between the fair value of the consideration paid upon redemption and the carrying value of the preferred units. As such, NRP reduced net income available to common unitholders and the general partner by $ i 16.2 million during the three months ended March 31, 2023. 

The following table shows the cash distributions declared and paid to common and preferred unitholders during the three months ended March 31, 2023 and 2022, respectively:

5.    Net Income Per Common Unit

Basic net income per common unit is computed by dividing net income, after considering income attributable to preferred unitholders, the difference between the fair value of the consideration paid upon redemption and the carrying value of the preferred units and the general partner’s general partner interest, by the weighted average number of common units outstanding. Diluted net income per common unit includes the effect of NRP's preferred units, warrants, and unvested unit-based awards if the inclusion of these items is dilutive.

The dilutive effect of the preferred units is calculated using the if-converted method. Under the if-converted method, the preferred units are assumed to be converted at the beginning of the period, and the resulting common units are included in the denominator of the diluted net income per unit calculation for the period being presented. Distributions declared in the period and undeclared distributions on the preferred units that accumulated during the period are added back to the numerator for purposes of the if-converted calculation. The calculation of diluted net income per common unit for the three months ended March 31, 2023 includes the assumed conversion of the remaining preferred units while it does not include the assumed conversion of the preferred units that were redeemed during the first quarter of 2023 as the inclusion of these units would be anti-dilutive. The calculation of diluted net income per common unit for the three months ended March 31, 2022 includes the assumed conversion of the preferred units.

The dilutive effect of the warrants is calculated using the treasury stock method, which assumes that the proceeds from the exercise of these instruments are used to purchase common units at the average market price for the period. The calculation of diluted net income per common unit for the three months ended March 31, 2023 and 2022 includes the net settlement of warrants to purchase  i 0.75 million common units at a strike price of $ i 22.81 and the net settlement of warrants to purchase  i 2.25 million common units with a strike price of $ i 34.00.

The following table reconciles the numerator and denominator of the basic and diluted net income per common unit computations and calculates basic and diluted net income per common unit:

6.    Segment Information

The Partnership's segments are strategic business units that offer distinct products and services to different customers in different geographies within the U.S. and that are managed accordingly. NRP has the following  i two operating segments:

Mineral Rights—consists of mineral interests and other subsurface rights across the United States. NRP's ownership provides critical inputs for the manufacturing of steel, electricity and basic building materials, as well as opportunities for carbon sequestration and renewable energy. The Partnership is working to strategically redefine its business as a key player in the transitional energy economy in the years to come.

Soda Ash—consists of the Partnership's  i 49% non-controlling equity interest in Sisecam Wyoming, a trona ore mining operation and soda ash refinery in the Green River Basin of Wyoming. Sisecam Wyoming mines trona and processes it into soda ash that is sold both domestically and internationally to the glass and chemicals industries.

Direct segment costs and certain other costs incurred at the corporate level that are identifiable and that benefit the Partnership's segments are allocated to the operating segments accordingly. These allocated costs generally include salaries and benefits, insurance, property taxes, legal, royalty, information technology and shared facilities services and are included in operating and maintenance expenses on the Partnership's Consolidated Statements of Comprehensive Income.

Corporate and Financing includes functional corporate departments that do not earn revenues. Costs incurred by these departments include interest and financing, corporate headquarters and overhead, centralized treasury, legal and accounting and other corporate-level activity not specifically allocated to a segment and are included in general and administrative expenses on the Partnership's Consolidated Statements of Comprehensive Income.

The following table summarizes certain financial information for each of the Partnership's business segments:

7.    Equity Investment 

The Partnership accounts for its  i 49% investment in Sisecam Wyoming using the equity method of accounting. Activity related to this investment is as follows: 

The following table represents summarized financial information for Sisecam Wyoming as derived from their respective unaudited financial statements for the three months ended March 31, 2023 and 2022: