# EDGAR Filing Document

**Accession Number:** 0002052113
**File Stem:** 0001193125-26-035886
**Filing Date:** 2026-2
**Character Count:** 8466
**Document Hash:** 719dd3fcd16f2a27ecd0233b977279be
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-035886.hdr.sgml**: 20260203

**ACCESSION NUMBER**: 0001193125-26-035886

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260130

**FILED AS OF DATE**: 20260203

**DATE AS OF CHANGE**: 20260203

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** BlackRock Portfolio Management LLC
- **CENTRAL INDEX KEY:** 0002052113

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43088
- **FILM NUMBER:** 26594585

**BUSINESS ADDRESS:**
- **STREET 1:** 50 HUDSON YARDS
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10001
- **BUSINESS PHONE:** (212) 810-5800

**MAIL ADDRESS:**
- **STREET 1:** 50 HUDSON YARDS
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10001
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Yellowstone Midco Holdings II, LLC
- **CENTRAL INDEX KEY:** 0002086587
- **STANDARD INDUSTRIAL CLASSIFICATION:** GUIDED MISSILES & SPACE VEHICLES & PARTS [3760]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 1449 7TH STREET, SUITE 425
- **CITY:** DENVER
- **STATE:** CO
- **ZIP:** 80204
- **BUSINESS PHONE:** 720-537-2655

**MAIL ADDRESS:**
- **STREET 1:** 1449 7TH STREET, SUITE 425
- **CITY:** DENVER
- **STATE:** CO
- **ZIP:** 80204

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>BlackRock Portfolio Management LLC<br><sub>(Last) (First) (Middle)</sub><br>50 HUDSON YARDS<br><sub>(Street)</sub><br>NEW YORK, NY 10001<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-01-30 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Yellowstone Midco Holdings II, LLC [ YSS ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-01-30 |  | P |  | 752500 | A | $34.00 | 17846934 | I | See footnote<sup>(1)(2)(3)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Represents shares of the Issuer's common stock held by the following funds and accounts under management by certain subsidiaries of BlackRock, Inc.: BlackRock Private Equity Co-Investments, 2021 Aggregator Cayman Ltd., BlackRock Growth Equity Fund Master Cayman Aggregator Ltd., BR POF IV CAYMAN MASTER FUND, L.P., BlackRock Private Opportunities Fund IV, L.P., BlackRock Private Opportunities Fund IV Master SCSp, TSCL Private Markets Cayman Fund Ltd., 1885 Private Opportunities Cayman Fund, Ltd., Heathrow Forest Opportunities Fund, L.P., Lincoln Pension Private Equity BR, L.P., NHRS Private Opportunities Fund, L.P., NDSIB Private Opportunities Fund Cayman Ltd., Mutual of Omaha OF Cayman, Ltd., BlackRock ERI Private Opportunities Master SCSp, Sullivan Way POF Cayman, Ltd, Total Alternatives Fund - Private Equity (B) LP, Total Alternatives Fund - Private Equity LP, 1824 Private Equity Fund, L.P., Tango Capital Opportunities Fund, L.P., BlackRock Private Investments Fund,

(2) (Continued from footnote 1) OV Private Opportunities Cayman, Ltd., SONJ Opportunities Cayman, Ltd., Red River Direct Investment Fund III, L.P., MB BlackRock Holdings Cayman Ltd. and certain other funds and accounts managed by BlackRock Financial Management, Inc., BlackRock Institutional Trust Company, National Association, BlackRock Investment Management (UK) Limited and BlackRock Investment Management, LLC (collectively, the "Advised Funds and Accounts"). Each of BlackRock Portfolio Management LLC, the Advised Funds and Accounts and their respective direct or indirect managers, general partners and portfolio managers who share voting and investment power over the shares held by the Advised Funds and Accounts expressly disclaim beneficial ownership of the shares of common stock held by the Advised Funds and Accounts, except to the extent of their pecuniary interest therein,

(3) (Continued from footnote 2) and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purposes.

**Remarks:**
In accordance with SEC Release No. 34-39538 (January 12, 1998), BlackRock Portfolio Management LLC is reporting Issuer securities beneficially owned, or deemed to be beneficially owned, by certain business units (collectively, the "Reporting Business Units") of BlackRock, Inc. and its subsidiaries and affiliates. This filing does not include Issuer securities, if any, beneficially owned by other business units whose beneficial ownership of securities is disaggregated from that of the Reporting Business Units in accordance with such release.

**Signature:** BlackRock Portfolio Management LLC, By: /s/ David Maryles, Authorized Signatory  
**Date:** 2026-02-03

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**