# Relationship history for MSHA mine 0402315

Current hierarchy: **Lhoist Group → Chemstar Lime Company → Richmond Mill/Stockton**

- 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

- **operator_operates_mine:** Flintkote Company → Richmond Mill/Stockton; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **controller_controls_mine:** Flintkote Company → Richmond Mill/Stockton; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Flintkote Company → Flintkote Company; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **operator_operates_mine:** Genstar Lime Company → Richmond Mill/Stockton; 1980-04-07 to 1986-12-03; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → Richmond Mill/Stockton; 1980-04-07 to 1986-12-03; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Genstar Lime Company; 1980-04-07 to 1986-12-03; source msha-controller-operator-history
- **operator_operates_mine:** Chemstar Lime Company → Richmond Mill/Stockton; 1986-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chemical Lime Company → Richmond Mill/Stockton; 1986-12-04 to 1998-12-30; source msha-controller-operator-history
- **controller_controls_operator:** Chemical Lime Company → Chemstar Lime Company; 1986-12-04 to 1998-12-30; source msha-controller-operator-history
- **controller_controls_mine:** Lhoist Group → Richmond Mill/Stockton; 1998-12-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lhoist Group → Chemstar Lime Company; 1998-12-31 to current/open; source msha-controller-operator-history