| Type | Filed | Filer | Subject | Shares Owned | Percent Owned | |
|---|---|---|---|---|---|---|
| SC 13G/A | 2017-02-09 | DIMENSIONAL FUND ADVISORS LP | DAWSON OPERATING CO | 0 | 0.0% | EDGAR |
| SC 13G/A | 2016-02-11 | PARADIGM CAPITAL MANAGEMENT INC/NY | DAWSON OPERATING CO | - | 0.0% | EDGAR |
| SC 13G/A | 2016-02-09 | DIMENSIONAL FUND ADVISORS LP | DAWSON OPERATING CO | 0 | 0.0% | EDGAR |
| SC 13G | 2015-02-12 | PARADIGM CAPITAL MANAGEMENT INC/NY | DAWSON OPERATING CO | 765,100 | 9.5% | EDGAR |
| SC 13G/A | 2015-02-05 | DIMENSIONAL FUND ADVISORS LP | DAWSON GEOPHYSICAL CO | 624,623 | 7.7% | EDGAR |
| SC 13G | 2015-02-04 | GRACE & WHITE INC /NY | DAWSON GEOPHYSICAL CO | 9 | 11.0% | EDGAR |
| SC 13G/A | 2015-01-30 | BlackRock Inc. | DAWSON GEOPHYSICAL CO | 519,359 | 6.4% | EDGAR |
| SC 13G/A | 2014-02-12 | VANGUARD GROUP INC | DAWSON GEOPHYSICAL CO | 270,139 | 3.4% | EDGAR |
| SC 13G/A | 2014-02-10 | DIMENSIONAL FUND ADVISORS LP | DAWSON GEOPHYSICAL CO | 634,853 | 7.9% | EDGAR |
| SC 13G/A | 2014-01-28 | BlackRock Inc. | DAWSON GEOPHYSICAL CO | 595,116 | 7.4% | EDGAR |
| SC 13G/A | 2013-02-11 | VANGUARD GROUP INC | DAWSON GEOPHYSICAL CO | 443,845 | 5.5% | EDGAR |
| SC 13G/A | 2013-02-11 | DIMENSIONAL FUND ADVISORS LP | DAWSON GEOPHYSICAL CO | 579,179 | 7.2% | EDGAR |
| SC 13G/A | 2013-02-08 | BlackRock Inc. | DAWSON GEOPHYSICAL CO | 584,849 | 7.3% | EDGAR |
| SC 13G/A | 2013-01-29 | ROYCE & ASSOCIATES LLC | DAWSON GEOPHYSICAL CO | 375,800 | 4.7% | EDGAR |
| SC 13G/A | 2012-02-14 | DIMENSIONAL FUND ADVISORS LP | DAWSON GEOPHYSICAL CO | 550,943 | 7.0% | EDGAR |
| SC 13G/A | 2012-02-13 | BlackRock Inc. | DAWSON GEOPHYSICAL CO | 442,664 | 5.6% | EDGAR |
| SC 13G | 2012-02-08 | VANGUARD GROUP INC | DAWSON GEOPHYSICAL CO | 399,823 | 5.0% | EDGAR |
| SC 13G/A | 2012-01-11 | ROYCE & ASSOCIATES LLC | DAWSON GEOPHYSICAL CO | 413,900 | 5.2% | EDGAR |
| SC 13G/A | 2011-02-11 | DIMENSIONAL FUND ADVISORS LP | DAWSON GEOPHYSICAL CO | 518,884 | 6.6% | EDGAR |
| SC 13G | 2011-02-09 | BEDDOW CAPITAL MANAGEMENT INC | DAWSON GEOPHYSICAL CO | 408,173 | 5.2% | EDGAR |