# Relationship history for MSHA mine 4103197

Current hierarchy: **Rasmussen Group Inc → Viking Aggregates → Porter Plant & 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Hallett Construction Company → Porter Plant & Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hallett Construction Company → Porter Plant & Pit; 1983-09-01 to 1986-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Hallett Construction Company → Hallett Construction Company; 1983-09-01 to 1986-10-13; source msha-controller-operator-history
- **controller_controls_mine:** Mid America Materials Company → Porter Plant & Pit; 1986-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hallett Materials → Porter Plant & Pit; 1986-10-14 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Mid America Materials Company → Hallett Materials; 1986-10-14 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Holding Company → Porter Plant & Pit; 1991-03-15 to 2024-04-18; source msha-controller-operator-history
- **operator_operates_mine:** Hallett Materials → Porter Plant & Pit; 1999-04-01 to 2001-08-10; source msha-controller-operator-history
- **controller_controls_mine:** Rasmussen Group Inc → Porter Plant & Pit; 1999-04-01 to 2001-08-10; source msha-controller-operator-history
- **controller_controls_operator:** Rasmussen Group Inc → Hallett Materials; 1999-04-01 to 2001-08-10; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Porter Plant & Pit; 2001-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Hallett Materials; 2001-08-11 to 2001-08-10; source msha-controller-operator-history
- **operator_operates_mine:** Hallett Materials → Porter Plant & Pit; 2001-08-11 to 2025-10-26; source msha-controller-operator-history
- **controller_controls_mine:** Rasmussen Group Inc → Porter Plant & Pit; 2001-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rasmussen Group Inc → Hallett Materials; 2001-08-11 to 2025-10-26; source msha-controller-operator-history
- **controller_controls_mine:** Rasmussen Group Inc → Porter Plant & Pit; 2024-04-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Viking Aggregates → Porter Plant & Pit; 2025-10-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Holding Company → Viking Aggregates; 2025-10-27 to 2024-04-18; source msha-controller-operator-history
- **controller_controls_operator:** Rasmussen Group Inc → Viking Aggregates; 2025-10-27 to current/open; source msha-controller-operator-history