DAWSON GEOPHYSICAL CO — Director's Dealing 2006

May 8, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGCI)
CIK: 0000799165
Period of Report: 2006-05-05

Reporting Person: HURTT WILLIAM C JR (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-05-05	Common Stock	S	1900	$15.25	Disposed	768135	Direct
2006-05-05	Common Stock	G	22000	—	Disposed	746135	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	11340	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Warrants (Series C2)	$.95	2007-12-15	Common Stock (5460)	5460	Direct

Footnotes

F1: Reporting Person disclaims beneficial ownership of shares owned by spouse.

F2: Includes 15,700 shares of common stock held in Reporting Person's IRA.

F3: Not applicable.