# EDGAR Filing Document

**Accession Number:** 0000724004
**File Stem:** 0000724004-26-000059
**Filing Date:** 2026-6
**Character Count:** 6225
**Document Hash:** 4ee201e8125d69742428c422f33cb913
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000724004-26-000059.hdr.sgml**: 20260616

**ACCESSION NUMBER**: 0000724004-26-000059

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260615

**FILED AS OF DATE**: 20260616

**DATE AS OF CHANGE**: 20260616

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Crennen Lyndsey Elizabeth
- **CENTRAL INDEX KEY:** 0002140665

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-11740
- **FILM NUMBER:** 261095399

**MAIL ADDRESS:**
- **STREET 1:** 2850 S CLARKSON CIRCLE
- **CITY:** ENGLEWOOD
- **STATE:** CO
- **ZIP:** 80113
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MESA LABORATORIES INC /CO/
- **CENTRAL INDEX KEY:** 0000724004
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 840872291
- **STATE OF INCORPORATION:** CO
- **FISCAL YEAR END:** 0331

**BUSINESS ADDRESS:**
- **STREET 1:** 12100 W 6TH AVE
- **CITY:** LAKEWOOD
- **STATE:** CO
- **ZIP:** 80228
- **BUSINESS PHONE:** 3039878000

**MAIL ADDRESS:**
- **STREET 1:** 12100 W 6TH AVE
- **CITY:** LAKEWOOD
- **STATE:** CO
- **ZIP:** 80228

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MESA LABORATORIES INC /CO
- **DATE OF NAME CHANGE:** 19951117

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MESA MEDICAL INC
- **DATE OF NAME CHANGE:** 19921123

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

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Crennen Lyndsey Elizabeth<br><sub>(Last) (First) (Middle)</sub><br>2850 S CLARKSON CIRCLE<br><sub>(Street)</sub><br>ENGLEWOOD, CO 80113<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>MESA LABORATORIES INC /CO/ [ MLAB ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-06-15 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [ ] 10% Owner<br>[X] Officer (give title below)   [ ] Other (specify below)<br>_Chief Accounting Officer_ | **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 Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Common Stock | 1863 | D |  |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| Restricted Stock Unit - 1<sup>(3)</sup> | 2026-06-21<sup>(1)</sup> | <sup>(2)</sup> | Common Stock | 125 | $0 | D |  |
| Restricted Stock Unit - 2<sup>(3)</sup> | 2026-06-18<sup>(4)</sup> | <sup>(2)</sup> | Common Stock | 465 | $0 | D |  |
| Restricted Stock Units - 3<sup>(3)</sup> | 2026-06-19<sup>(5)</sup> | <sup>(2)</sup> | Common Stock | 735 | $0 | D |  |
| Restricted Stock Units<sup>(3)</sup> | 2027-06-13<sup>(6)</sup> | <sup>(2)</sup> | Common Stock | 542 | $0 | D |  |
| Restricted Stock Units - 5 | 2027-03-02<sup>(7)</sup> | <sup>(2)</sup> | Common Stock | 1800 | $0 | D |  |
| Restricted Stock Units 6<sup>(3)</sup> | 2027-06-15<sup>(8)</sup> | <sup>(2)</sup> | Common Stock | 1443 | $0 | D |  |
| NSO -1 | 2022-09-01<sup>(9)</sup> | 2027-09-01 | Common Stock | 369 | $268.85 | D |  |
| NSO - 2 | 2025-06-15<sup>(10)</sup> | 2028-06-15 | Common Stock | 488 | $185.57 | D |  |
| NSO - 3 | 2024-06-21<sup>(11)</sup> | 2029-06-21 | Common Stock | 646 | $131.67 | D |  |

---

### Footnotes:

(1) Last tranche of the grant vests on June 21, 2026

(2) Not Applicable

(3) Each RSU represents a contingent right to receive one share of the Issuer's common stock

(4) RSUs that vest 233 shares on June 18, 2026 and 232 shares that vest on June 18, 2027

(5) RSUs that vest 368 shares on June 19, 2026 and 367 shares that vest on June 19, 2027

(6) RSUs that vest 271 shares on June 13, 2027 and 271 shares on June 13, 2028

(7) RSUs that vest 612 shares on March 2, 2027 and 594 shares that vest on each of March 2, 2028 and March 2, 2029

(8) RSUs that vest 34% on June 15, 2027, 33% on June 8, 2028 and 33% on June 8, 2029

(9) Non qualified stock options that were fully vested as of June 15, 2024

(10) Non qualified stock options that were fully vested as of June 15, 2025

(11) NSO's that will fully vest on June 21, 2026

**Signature:** John Sakys under Power of Attorney by Lyndsey Crennen  
**Date:** 2026-06-16

### 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.**