# Relationship history for MSHA mine 4500671

Current hierarchy: **R B Pamplin Corp → Pacific Northwest Aggregates Inc → Avery Pit**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Pacific Northwest Aggregates Inc → Avery Pit; 1950-01-01 to 1990-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Craig  Warnock → Avery Pit; 1950-01-01 to 1994-10-03; source msha-controller-operator-history
- **controller_controls_operator:** Craig  Warnock → Pacific Northwest Aggregates Inc; 1950-01-01 to 1990-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Dalles Concrete Inc → Avery Pit; 1990-12-01 to 1992-10-26; source msha-controller-operator-history
- **controller_controls_mine:** Fred W  Ashley → Avery Pit; 1990-12-01 to 1996-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Fred W  Ashley → Dalles Concrete Inc; 1990-12-01 to 1992-10-26; source msha-controller-operator-history
- **operator_operates_mine:** Pacific Northwest Aggregates Inc → Avery Pit; 1992-10-27 to 1994-10-03; source msha-controller-operator-history
- **controller_controls_operator:** Craig  Warnock → Pacific Northwest Aggregates Inc; 1992-10-27 to 1994-10-03; source msha-controller-operator-history
- **operator_operates_mine:** Dalles Concrete Inc → Avery Pit; 1994-10-04 to 1996-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Fred W  Ashley → Dalles Concrete Inc; 1994-10-04 to 1996-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Pacific Northwest Aggregates Inc → Avery Pit; 1996-12-01 to 1999-02-23; source msha-controller-operator-history
- **controller_controls_mine:** Randy A Dyche et al → Avery Pit; 1996-12-01 to 1999-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Randy A Dyche et al → Pacific Northwest Aggregates Inc; 1996-12-01 to 1999-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Tripco Inc → Avery Pit; 1999-02-24 to 2000-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Ross  Triplett → Avery Pit; 1999-02-24 to 2021-06-29; source msha-controller-operator-history
- **controller_controls_operator:** Ross  Triplett → Tripco Inc; 1999-02-24 to 2000-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Pacific Northwest Aggregates Inc → Avery Pit; 2000-07-01 to 2001-03-18; source msha-controller-operator-history
- **controller_controls_mine:** Ty  Ross et al → Avery Pit; 2000-07-01 to 2001-03-18; source msha-controller-operator-history
- **controller_controls_operator:** Ty  Ross et al → Pacific Northwest Aggregates Inc; 2000-07-01 to 2001-03-18; source msha-controller-operator-history
- **operator_operates_mine:** Pacific Northwest Aggregates Inc → Avery Pit; 2001-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ross Island Sand & Gravel Company → Avery Pit; 2001-03-19 to 2001-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Ross Island Sand & Gravel Company → Pacific Northwest Aggregates Inc; 2001-03-19 to 2001-12-31; source msha-controller-operator-history
- **controller_controls_mine:** R B Pamplin Corp → Avery Pit; 2002-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** R B Pamplin Corp → Pacific Northwest Aggregates Inc; 2002-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Case E  Stedham → Avery Pit; 2021-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Case E  Stedham → Tripco Inc; 2021-06-30 to 2000-06-30; source msha-controller-operator-history