# Relationship history for MSHA mine 1001871

Current hierarchy: **Dennis  O'Hagan; Lori  O'Hagan → Conmat Group Inc → Washplant**

- 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:** Consolidated Construction Materials Inc → Washplant; 1991-07-01 to 1993-05-17; source msha-controller-operator-history
- **controller_controls_mine:** Bob  Bersher → Washplant; 1991-07-01 to 1993-05-17; source msha-controller-operator-history
- **controller_controls_operator:** Bob  Bersher → Consolidated Construction Materials Inc; 1991-07-01 to 1993-05-17; source msha-controller-operator-history
- **operator_operates_mine:** Conmat → Washplant; 1993-05-18 to 2008-09-02; source msha-controller-operator-history
- **controller_controls_mine:** Colfax Excavators North Inc → Washplant; 1993-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colfax Excavators North Inc → Conmat; 1993-05-18 to 2008-09-02; source msha-controller-operator-history
- **controller_controls_mine:** Janelle  Swenson  et al → Washplant; 2006-11-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Conmat Inc → Washplant; 2008-09-03 to 2023-06-18; source msha-controller-operator-history
- **controller_controls_operator:** Janelle  Swenson  et al → Conmat Inc; 2008-09-03 to 2023-06-18; source msha-controller-operator-history
- **controller_controls_operator:** Liann  Swenson  et al → Conmat Inc; 2008-09-03 to 2023-06-18; source msha-controller-operator-history
- **operator_operates_mine:** Conmat Group Inc → Washplant; 2023-06-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Liann  Swenson → Washplant; 2023-06-19 to 2024-01-24; source msha-controller-operator-history
- **controller_controls_operator:** Liann  Swenson → Conmat Group Inc; 2023-06-19 to 2024-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Dennis  O'Hagan et al → Washplant; 2024-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis  O'Hagan et al → Conmat Group Inc; 2024-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lori  O'Hagan et al → Conmat Group Inc; 2024-01-25 to current/open; source msha-controller-operator-history