UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
T.G.C. INDUSTRIES INC. (TGE)
(Name of Issuer)
COM
(Title of Class of Securities)
872417308
(CUSIP Number)
________________________________________________________________________________
1) Names of Reporting Persons, IRS Identification Nos. of Above Persons:
OTR - Nominee Name for The State Teachers Retirement Board of Ohio, 31-1312155
________________________________________________________________________________
2) Check the appropriate box if a member of a group* (a) [_] (b) [_]
________________________________________________________________________________
3) SEC Use Only
________________________________________________________________________________
4) Citizenship or Place of Organization
Columbus, Ohio
________________________________________________________________________________
Number of Shares Beneficially Owned by Each Reporting Person With
5) Sole Voting Power 900000
6) Shared Voting Power 0
7) Sole Dispositive Power 900000
8) Shared Dispositive Power 0
________________________________________________________________________________
9) Aggregate Amount Beneficially Owned by Each Reporting Person 900000
________________________________________________________________________________
10) Check if the Aggregate Amount in Row (9) Excludes Certain Shares* [_]
________________________________________________________________________________
11) Percent of Class Represented by Amount in Row (9) 5.73
________________________________________________________________________________
12) Type of Reporting Person* EP
________________________________________________________________________________
SCHEDULE 13G
________________________________________________________________________________
Item 1
(a) Name of Issuer
This Statement on Schedule 13G relates to the shares of Instrument
T.G.C. INDUSTRIES INC.
(b) Address of Issuer's Principal Executive Offices:
________________________________________________________________________________
Item 2
(a) Name of Person Filing:
This Statement is filed by
OTR - Nominee Name for The State Teachers Retirement Board of Ohio
(b) Address of Principal Business Office:
The business address of OTR - Nominee Name for The State Teachers Retirement Board of Ohio is
275 East Broad Street
Columbus, Ohio 43215
(c) Citizenship: Not Applicable
(d) Title of Class of Securities:
The securities are shares of COM .
(e) CUSIP No.:
The CUSIP Number for the investment is 872417308 .
________________________________________________________________________________
Item 3 Type of Person Filing:
STRS is an employee benefit plan established for teachers of the public schools of Ohio to provide retirement allowances and other benefits under the terms of Chapter 3307 of the Ohio Revised Code.
________________________________________________________________________________
Item 4 OWNERSHIP
(a) Amount Beneficially Owned:
STRS owns 900000 shares of T.G.C. INDUSTRIES INC.
(b) Percent of Class:
STRS believes that there are presently 15715000 outstanding shares of T.G.C. INDUSTRIES INC. ; therefore, STRS' ownership of 900000 shares of T.G.C. INDUSTRIES INC. stock is 5.73 percent of this class.
(c) Number of Shares As To Which Such Person Has Power:
(i) Sole power to vote or to direct the vote 900000
(ii) Shared power to vote or to direct the vote 0
(iii) Sole power to dispose or to direct the disposition of 900000
(iv) Shared power to dispose or to direct the disposition of 0 shares of T.G.C. INDUSTRIES INC. stock.
________________________________________________________________________________
Item 5 OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.
If this statements is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five (5) percent of the class of securities, check the following [ ].
________________________________________________________________________________
Item 6 OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON
Not Applicable
________________________________________________________________________________
Item 7 IDENTIFICATION AND CLASSIFICATION OF 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 CERTIFICATION
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of, and do not have the effect of, changing or influencing the control of the issuer of such securities, and were not acquired in connection with, or as a participant in, any transaction having such purposes or effect.
________________________________________________________________________________
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.
DATED: 1/5/2007
OTR - Nominee Name for The State Teachers Retirement Board of Ohio
275 East Broad Street
Columbus, Ohio 43215
STEPHEN A. MITCHELL
/s/Stephen A. Mitchell
...........................................
Stephen A. Mitchell
Deputy Executive Director, Investments
614-227-4003