| SC 13G/A | 2004-02-17 | FMR CORP | NORTHWEST PIPE CO | 655,800 | 10.0% | EDGAR |
| SC 13G/A | 2004-02-13 | FLEETBOSTON FINANCIAL CORP | NORTHWEST PIPE CO | 636,482 | 9.7% | EDGAR |
| SC 13G/A | 2004-02-13 | LIBERTY WANGER ASSET MANAGEMENT LP | NORTHWEST PIPE CO | 216,000 | 3.3% | EDGAR |
| SC 13G/A | 2004-02-12 | WELLINGTON MANAGEMENT CO LLP | NORTHWEST PIPE CO | 373,300 | 5.7% | EDGAR |
| SC 13G/A | 2004-02-06 | DIMENSIONAL FUND ADVISORS INC | NORTHWEST PIPE CO | 379,800 | 5.8% | EDGAR |
| SC 13G/A | 2004-02-03 | BECKER CAPITAL MANAGEMENT INC | NORTHWEST PIPE CO | 437,360 | 6.7% | EDGAR |
| SC 13G/A | 2004-01-20 | FRONTIER CAPITAL MANAGEMENT CO LLC | NORTHWEST PIPE CO | 397,800 | 6.1% | EDGAR |
| SC 13G/A | 2004-01-09 | WELLS FARGO & CO/MN | NORTHWEST PIPE CO | 861,465 | 13.1% | EDGAR |
| SC 13G | 2003-12-10 | WELLS FARGO & CO/MN | NORTHWEST PIPE CO | 872,265 | 13.3% | EDGAR |
| SC 13G/A | 2003-06-27 | FLEETBOSTON FINANCIAL CORP | NORTHWEST PIPE CO | 623,432 | 9.5% | EDGAR |
| SC 13G/A | 2003-06-13 | FLEETBOSTON FINANCIAL CORP | NORTHWEST PIPE CO | 889,232 | 13.6% | EDGAR |
| SC 13G/A | 2003-03-05 | BENSON ASSOCIATES LLC | NORTHWEST PIPE CO | 725,727 | 11.1% | EDGAR |
| SC 13G/A | 2003-02-14 | FLEETBOSTON FINANCIAL CORP | NORTHWEST PIPE CO | 543,132 | 8.3% | EDGAR |
| SC 13G | 2003-02-14 | FMR CORP | NORTHWEST PIPE CO | 354,888 | 5.4% | EDGAR |
| SC 13G/A | 2003-02-12 | WELLINGTON MANAGEMENT CO LLP | NORTHWEST PIPE CO | 497,800 | 7.6% | EDGAR |
| SC 13G | 2003-02-12 | LIBERTY WANGER ASSET MANAGEMENT LP | NORTHWEST PIPE CO | 395,000 | 6.0% | EDGAR |
| SC 13G/A | 2003-02-11 | DIMENSIONAL FUND ADVISORS INC | NORTHWEST PIPE CO | 450,100 | 6.9% | EDGAR |
| SC 13G/A | 2003-02-10 | HEARTLAND ADVISORS INC | NORTHWEST PIPE CO | 334,301 | 5.1% | EDGAR |
| SC 13G/A | 2003-02-10 | HEARTLAND ADVISORS INC | NORTHWEST PIPE CO | 296,201 | 4.5% | EDGAR |
| SC 13G/A | 2003-02-05 | FRONTIER CAPITAL MANAGEMENT CO LLC | NORTHWEST PIPE CO | 422,550 | 6.4% | EDGAR |