Mesa Laboratories (Common Stock) Schedule 13G: Long Path-related reporting persons report beneficial ownership of 311,703 shares, representing 5.6% of the class. Percentage ownership is based on 5,524,813 shares outstanding as of January 31, 2026.
The filing lists the owner as Long Path Smaller Companies Fund, LP with affiliated entities and two co-portfolio managers joining a joint filing. The shares are directly held by the Fund and the reporting parties disclaim beneficial ownership except for pecuniary interest.
Positive
None.
Negative
None.
Insights
Long Path reports a single 5.6% passive stake in Mesa Laboratories.
The Schedule 13G shows 311,703 shares held by Long Path Smaller Companies Fund, representing 5.6% of the outstanding common stock based on January 31, 2026 outstanding shares. The position is presented via affiliated entities and a joint filing agreement.
Holding scale is visible; cash-flow treatment or plans for sale are not stated in the excerpt. Subsequent filings would disclose any change in voting or disposition intent.
Reporting structure uses affiliated entities and a joint filing agreement.
The filing names Long Path Fund GP, Long Path Partners, Long Path Holdings LLC, and two individuals as reporting persons and includes a Joint Filing Agreement as Exhibit A. The Fund is the direct holder and the individuals disclaim beneficial ownership except for pecuniary interest.
Ownership is shown with shared voting and dispositive power of 311,703 shares; governance impact depends on future disclosures and any changes to voting alignment among the reporting persons.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Mesa Laboratories, Inc.
(Name of Issuer)
Common Stock, no par value
(Title of Class of Securities)
03/11/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
SCHEDULE 13G
CUSIP Number(s):
1
Names of Reporting Persons
Long Path Smaller Companies Fund, LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
311,703.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
311,703.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
311,703.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.6 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
1
Names of Reporting Persons
Long Path Fund GP, LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
311,703.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
311,703.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
311,703.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.6 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
1
Names of Reporting Persons
Long Path Partners, LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
311,703.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
311,703.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
311,703.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.6 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
1
Names of Reporting Persons
Long Path Holdings LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
311,703.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
311,703.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
311,703.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.6 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
1
Names of Reporting Persons
William Thomas Brennan
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
311,703.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
311,703.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
311,703.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.6 %
12
Type of Reporting Person (See Instructions)
IN, HC
SCHEDULE 13G
CUSIP Number(s):
1
Names of Reporting Persons
Brian Paul Nelson
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
311,703.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
311,703.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
311,703.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.6 %
12
Type of Reporting Person (See Instructions)
IN, HC
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Mesa Laboratories, Inc.
(b)
Address of issuer's principal executive offices:
12100 West Sixth Ave., Lakewood, CO 80228
Item 2.
(a)
Name of person filing:
This Schedule 13G is filed by (i) Long Path Smaller Companies Fund, LP (the "Fund"), (ii) Long Path Fund GP, LLC (the "Fund GP"), as the general partner of the Fund, (iii) Long Path Partners, LP (the "Adviser"), as the investment adviser to the Fund, (iv) Long Path Holdings LLC (the "Adviser GP"), as the general partner of the Adviser, (v) William Thomas Brennan, as the managing member of the Fund GP and the Adviser GP and co-portfolio manager of the Fund, and (vi) Brian Paul Nelson, as co-portfolio manager of the Fund and a member of the Adviser GP (each, a "Reporting Person" and collectively, the "Reporting Persons"). The agreement among the Reporting Persons to file the Schedule 13G jointly (the "Joint Filing Agreement") is filed herewith as Exhibit A. The shares reported herein are directly held by the Fund and each Reporting Person disclaims beneficial ownership of such shares except to the extent of its or his pecuniary interest therein.
(b)
Address or principal business office or, if none, residence:
c/o Long Path Partners, 1 Landmark Square, Suite 1920, Stamford, CT 06901
(c)
Citizenship:
The Fund is a Delaware limited partnership. The Fund GP is a Delaware limited liability company. The Adviser is a Delaware limited partnership. The Adviser GP is a Delaware limited liability company. William Thomas Brennan and Brian Paul Nelson are citizens of the United States.
(d)
Title of class of securities:
Common Stock, no par value
(e)
CUSIP No.:
59064R109
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
The information required by this paragraph is set forth in the cover pages to this Schedule 13G and is incorporated herein by reference.
(b)
Percent of class:
The information required by this paragraph is set forth in the cover pages to this Schedule 13G and is incorporated herein by reference. Percentage ownership is based on 5,524,813 shares of Common Stock outstanding as of January 31, 2026, as reported in the Issuer's Report on Form 10-Q for the period ended December 31, 2025 filed with the Securities and Exchange Commission on February 3, 2026.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
The information required by this paragraph is set forth in the cover pages to this Schedule 13G and is incorporated herein by reference.
(ii) Shared power to vote or to direct the vote:
The information required by this paragraph is set forth in the cover pages to this Schedule 13G and is incorporated herein by reference.
(iii) Sole power to dispose or to direct the disposition of:
The information required by this paragraph is set forth in the cover pages to this Schedule 13G and is incorporated herein by reference.
(iv) Shared power to dispose or to direct the disposition of:
The information required by this paragraph is set forth in the cover pages to this Schedule 13G and is incorporated herein by reference.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
Long Path Smaller Companies Fund, LP
Signature:
/s/ William Thomas Brennan
Name/Title:
William Thomas Brennan/Managing Member of Long Path Fund GP, LLC, its general partner
Date:
03/13/2026
Long Path Fund GP, LLC
Signature:
/s/ William Thomas Brennan
Name/Title:
William Thomas Brennan/Managing Member
Date:
03/13/2026
Long Path Partners, LP
Signature:
/s/ William Thomas Brennan
Name/Title:
William Thomas Brennan/Managing Member of Long Path Holdings LLC, its general partner
What stake in Mesa Laboratories (MLAB) does Long Path report?
Long Path reports beneficial ownership of 311,703 shares, or 5.6%. This percentage is calculated from 5,524,813 shares outstanding as of January 31, 2026, per the filing's reference.
Which Long Path entities are listed on the Schedule 13G for MLAB?
The filing lists Long Path Smaller Companies Fund, LP, Long Path Fund GP, LLC, Long Path Partners, LP, and Long Path Holdings LLC. Two individuals, William T. Brennan and Brian P. Nelson, join the joint filing.
Does the Schedule 13G indicate how Long Path will vote or sell MLAB shares?
No. The filing shows shared voting and dispositive power of 311,703 shares but does not state any plan to vote, sell, or otherwise dispose of the shares in this excerpt.
How is the 5.6% ownership percentage calculated in the filing?
The percentage is based on 5,524,813 shares outstanding as of January 31, 2026, cited from the issuer's Form 10-Q for the period ended December 31, 2025 as referenced in the Schedule 13G.
