UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
SCHEDULE 13G
(Rule13d-102)
UNDER THE SECURITIES EXCHANGE ACT OF 1934
NATURAL GAS SERVICES GROUP, INC.
--------------------------------
(Name of Issuer)
Common Stock, $.01 par value per share
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(Title of Class of Securities)
63886Q109
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(CUSIP Number)
December 31, 2006
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(Date of Event Which Requires Filing of This Statement)
Check the appropriate box to designate the rule pursuant to which
this Schedule is filed:
[x] Rule 13d-1(b)
[ ] Rule 13d-1(c)
[ ] Rule 13d-1(d)
*The remainder of this cover page shall be filled out for a
reporting person's initial filing on this form with respect to the subject
class of securities, and for any subsequent amendment containing
information which would alter the disclosures provided in a prior cover
page.
The information required in the remainder of this cover page shall
not be deemed to be "filed" for the purpose of Section 18 of the Securities
Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of
that section of the Act but shall be subject to all other provisions of the
Act (however, see the Notes).
CUSIP No. 63886Q109 SCHEDULE 13G Page 2 of 8
1 Name of Reporting Person Westcliff Capital Management, LLC
IRS Identification No. of Above Person EIN 77-0435868
2 Check the Appropriate Box if a member of a Group (a) [ ]
(b) [ ]
3 SEC USE ONLY
4 Citizenship or Place of Organization California
5 Sole Voting Power 0
NUMBER OF
SHARES 6 Shared Voting Power 927,150
BENEFICIALLY
OWNED BY EACH 7 Sole Dispositive Power 0
REPORTING
PERSON WITH 8 Shared Dispositive Power 927,150
9 Aggregate Amount Beneficially Owned by Each Reporting Person 927,150
10 Check Box if the Aggregate Amount in Row (9) Excludes Certain
Shares [ ]
11 Percent of Class Represented by Amount in Row 9 7.75%
12 Type of Reporting Person IA
CUSIP No. 63886Q109 SCHEDULE 13G Page 3 of 8
1 Name of Reporting Person Richard S. Spencer III
IRS Identification No. of Above Person
2 Check the Appropriate Box if a member of a Group (a) [ ]
(b) [ ]
3 SEC USE ONLY
4 Citizenship or Place of Organization United States
5 Sole Voting Power 0
NUMBER OF
SHARES 6 Shared Voting Power 927,150
BENEFICIALLY
OWNED BY EACH 7 Sole Dispositive Power 0
REPORTING
PERSON WITH 8 Shared Dispositive Power 927,150
9 Aggregate Amount Beneficially Owned by Each Reporting Person 927,150
10 Check Box if the Aggregate Amount in Row (9) Excludes Certain
Shares [ ]
11 Percent of Class Represented by Amount in Row 9 7.75%
12 Type of Reporting Person HC, IN
CUSIP No. 63886Q109 SCHEDULE 13G Page 4 of 8
Item 1(a). Name of Issuer:
Natural Gas Services Group, Inc.
Item 1(b). Address of Issuer's Principal Executive Offices:
2911 SCR 1260, Midland, Texas 79706
Item 2(a). Names of Persons Filing:
Westcliff Capital Management, LLC ("Westcliff LLC") and
Richard S. Spencer III ("Spencer", and collectively, the
"Filers").
Westcliff LLC and Spencer disclaim beneficial ownership of the
Stock (as defined below) except to the extent of their
respective pecuniary interests therein.
Item 2(b). Address of Principal Business Office or, if none, Residence:
200 Seventh Avenue, Suite 105, Santa Cruz, CA 95062
Item 2(c). Citizenship:
See Item 4 of the cover page for each Filer.
Item 2(d). Title of Class of Securities:
This Statement relates to the shares of common stock of the
Issuer (the "Stock").
Item 2(e). CUSIP Number:
458751104
Item 3. If this statement is filed pursuant to sections 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) [x] An investment adviser in accordance with section
240.13d-1(b)(1)(ii)(E);
CUSIP No. 63886Q109 SCHEDULE 13G Page 5 of 8
(f) [ ] An employee benefit plan or endowment fund in accordance
with section 240.13d-1(b)(1)(ii)(F);
(g) [x] A parent holding company or control person in accordance
with section 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) [ ] Group, in accordance with section 240.13d-1(b)(1)(ii)(J).
Item 4. Ownership.
See Items 5-9 and 11 of the cover page for each Filer.
Westcliff LLC, as investment manager of various client
accounts, and Spencer, as Westcliff LLC's manager and majority
owner, may be deemed to beneficially own the Stock owned by
such accounts, in that they may be deemed to have the power to
direct the voting or disposition of that Stock. Neither the
filing of this Schedule nor any of its contents shall be
deemed to constitute an admission that Westcliff LLC or
Spencer is, for any purpose, the beneficial owner of any Stock
to which this Schedule relates, and each of Westcliff LLC and
Spencer disclaims beneficial ownership as to that Stock,
except to the extent of his or its pecuniary interests
therein. Neither the filing of this Schedule nor any of its
contents shall be deemed to constitute an admission that any
of the other individual officers and members of Westcliff LLC
is, for any purpose, the beneficial owner of any of the Stock
to which this Schedule relates, and such beneficial ownership
is expressly disclaimed.
Item 5. Ownership of Five Percent or Less of a Class.
Not Applicable.
Item 6. Ownership of More Than Five Percent on Behalf of Another
Person.
Westcliff LLC is the investment manager of one or more
investment partnerships, pooled investment vehicles and/or
other client accounts that beneficially hold the Stock and, in
that capacity, has been granted the authority to dispose of
and vote the Stock held by those accounts. The client
accounts have the right to receive (or the power to direct the
receipt of) dividends received in connection with ownership of
the Stock and the proceeds from the sale of the Stock. No
single client's holdings exceed five percent of the Stock.
CUSIP No. 63886Q109 SCHEDULE 13G Page 6 of 8
Item 7. Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on by the Parent Holding
Company.
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, each of the signatories certifies that, to
the best of its knowledge and belief, the securities referred
to above were acquired and are held in the ordinary course of
business and 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.
CUSIP No. 63886Q109 SCHEDULE 13G Page 7 of 8
Signatures
After reasonable inquiry and to the best of its knowledge
and belief, each of the signatories certifies that the information
set forth in this statement is true, complete and correct.
Dated: February 5, 2007
WESTCLIFF CAPITAL MANAGEMENT,
LLC
By: /s/ Richard S. Spencer III
---------------------------
Richard S. Spencer III
Manager
RICHARD S. SPENCER III
/s/ Richard S. Spencer III
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Richard S. Spencer III
CUSIP No. 63886Q109 SCHEDULE 13G Page 8 of 8
EXHIBIT A
JOINT FILING UNDERTAKING
The undersigned, being authorized thereunto, hereby execute this
agreement as an exhibit to this Schedule 13G to evidence the agreement of
the below-named parties, in accordance with rules promulgated pursuant to
the Securities Exchange Act of 1934, to file this Schedule, as it may be
amended, jointly on behalf of each of such parties.
Dated: February 5, 2007 WESTCLIFF CAPITAL MANAGEMENT,
LLC
By: /s/ Richard S. Spencer III
---------------------------
Richard S. Spencer III
Manager
RICHARD S. SPENCER III
/s/ Richard S. Spencer III
---------------------------
Richard S. Spencer III