All 3 companies
A–Z by legal name| Company | Registry number | Registered | Status | City |
|---|---|---|---|---|
| TETRA TECH HEI, INC. | 0588417 | 2004-06-16 | Inactive | PASADENA |
| TETRA TECH TECHNICAL SERVICES, INC. | 0591050 | 2004-07-26 | Active | PASADENA |
| THE RULE COMPANY, INCORPORATED | 0600594 | 2004-12-07 | Inactive | PASADENA |