| Type | Filed | Filer | Subject | Shares Owned | Percent Owned | |
|---|---|---|---|---|---|---|
| SC 13G/A | 2024-02-09 | DIMENSIONAL FUND ADVISORS LP | NORTHWEST PIPE CO | 755,883 | 7.5% | EDGAR |
| SC 13G/A | 2024-01-24 | ROYCE & ASSOCIATES LP | NORTHWEST PIPE CO | 920,534 | 9.2% | EDGAR |
| SC 13G/A | 2024-01-23 | BlackRock Inc. | NORTHWEST PIPE CO | 1,176,547 | 11.7% | EDGAR |
| SC 13G/A | 2023-07-07 | BlackRock Inc. | NORTHWEST PIPE CO | 1,055,320 | 10.6% | EDGAR |
| SC 13G/A | 2023-02-10 | DIMENSIONAL FUND ADVISORS LP | NORTHWEST PIPE CO | 753,286 | 7.6% | EDGAR |
| SC 13G/A | 2023-01-24 | ROYCE & ASSOCIATES LP | NORTHWEST PIPE CO | 925,799 | 9.3% | EDGAR |
| SC 13G/A | 2023-01-24 | BlackRock Inc. | NORTHWEST PIPE CO | 967,934 | 9.8% | EDGAR |
| SC 13G | 2022-06-09 | BlackRock Inc. | NORTHWEST PIPE CO | 1,125,709 | 11.4% | EDGAR |
| SC 13G/A | 2022-02-08 | DIMENSIONAL FUND ADVISORS LP | NORTHWEST PIPE CO | 717,583 | 7.3% | EDGAR |
| SC 13G/A | 2022-02-01 | BlackRock Inc. | NORTHWEST PIPE CO | 842,506 | 8.5% | EDGAR |
| SC 13G/A | 2022-01-25 | ROYCE & ASSOCIATES LP | NORTHWEST PIPE CO | 1,156,426 | 11.7% | EDGAR |
| SC 13G/A | 2021-02-12 | DIMENSIONAL FUND ADVISORS LP | NORTHWEST PIPE CO | 795,340 | 8.1% | EDGAR |
| SC 13G/A | 2021-02-10 | VANGUARD GROUP INC | NORTHWEST PIPE CO | 474,246 | 4.8% | EDGAR |
| SC 13G/A | 2021-01-29 | BlackRock Inc. | NORTHWEST PIPE CO | 811,758 | 8.3% | EDGAR |
| SC 13G/A | 2021-01-06 | ROYCE & ASSOCIATES LP | NORTHWEST PIPE CO | 1,027,554 | 10.5% | EDGAR |
| SC 13G/A | 2020-02-12 | DIMENSIONAL FUND ADVISORS LP | NORTHWEST PIPE CO | 804,151 | 8.2% | EDGAR |
| SC 13G | 2020-02-11 | VANGUARD GROUP INC | NORTHWEST PIPE CO | 488,032 | 5.0% | EDGAR |
| SC 13G/A | 2020-02-05 | BlackRock Inc. | NORTHWEST PIPE CO | 707,477 | 7.3% | EDGAR |
| SC 13G/A | 2020-01-29 | ROYCE & ASSOCIATES LP | NORTHWEST PIPE CO | 812,815 | 8.3% | EDGAR |
| SC 13G/A | 2019-02-13 | WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC | NORTHWEST PIPE CO | 0 | 0.0% | EDGAR |