| Type | Filed | Filer | Subject | Shares Owned | Percent Owned | |
|---|---|---|---|---|---|---|
| SC 13G/A | 2003-02-05 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 649,527 | 9.9% | EDGAR |
| SC 13G/A | 2003-02-04 | BECKER CAPITAL MANAGEMENT INC | NORTHWEST PIPE CO | 393,710 | 6.0% | EDGAR |
| SC 13G/A | 2003-01-29 | TAGMYER WILLIAM R | NORTHWEST PIPE CO | 343,656 | 5.1% | EDGAR |
| SC 13G | 2002-04-11 | TAGMYER WILLIAM R | NORTHWEST PIPE CO | 336,598 | 5.1% | EDGAR |
| SC 13G/A | 2002-02-14 | FLEETBOSTON FINANCIAL CORP | NORTHWEST PIPE CO | 575,360 | 8.8% | EDGAR |
| SC 13G/A | 2002-02-14 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 535,427 | 8.2% | EDGAR |
| SC 13G/A | 2002-02-12 | WELLINGTON MANAGEMENT CO LLP | NORTHWEST PIPE CO | 497,800 | 7.6% | EDGAR |
| SC 13G/A | 2002-02-12 | DIMENSIONAL FUND ADVISORS INC | NORTHWEST PIPE CO | 468,500 | 7.2% | EDGAR |
| SC 13G/A | 2002-02-08 | FRONTIER CAPITAL MANAGEMENT CO LLC /ADV | NORTHWEST PIPE CO | 397,560 | 5.9% | EDGAR |
| SC 13G/A | 2002-02-07 | BECKER CAPITAL MANAGEMENT INC | NORTHWEST PIPE CO | 484,250 | 7.4% | EDGAR |
| SC 13G/A | 2002-01-16 | HEARTLAND ADVISORS INC | NORTHWEST PIPE CO | 9 | 11.0% | EDGAR |
| SC 13G/A | 2001-02-14 | FRONTIER CAPITAL MANAGEMENT CO INC /ADV | NORTHWEST PIPE CO | 471,530 | 7.1% | EDGAR |
| SC 13G | 2001-02-14 | FLEETBOSTON FINANCIAL CORP | NORTHWEST PIPE CO | 551,860 | 8.5% | EDGAR |
| SC 13G/A | 2001-02-13 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 466,327 | 7.2% | EDGAR |
| SC 13G | 2001-02-13 | WELLINGTON MANAGEMENT CO LLP | NORTHWEST PIPE CO | 640,000 | 9.8% | EDGAR |
| SC 13G | 2001-02-12 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 466,327 | 7.2% | EDGAR |
| SC 13G | 2001-02-02 | DIMENSIONAL FUND ADVISORS INC | NORTHWEST PIPE CO | 449,600 | 6.9% | EDGAR |
| SC 13G/A | 2001-01-30 | BECKER CAPITAL MANAGEMENT INC | NORTHWEST PIPE CO | 439,167 | 6.8% | EDGAR |
| SC 13G | 2000-02-16 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 386,827 | 6.0% | EDGAR |
| SC 13G | 2000-02-16 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 386,827 | 6.0% | EDGAR |