# Relationship history for MSHA mine 4606992

Current hierarchy: **Costain Group PLC → Nix Mining Company → Spruce Run Surface Mine**

- 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

- **controller_controls_mine:** Graybeal Carl N & Jack L Williams → Spruce Run Surface Mine; 1981-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** G & W Equipment Leasing Inc → Spruce Run Surface Mine; 1985-09-01 to 1987-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Graybeal Carl N & Jack L Williams → G & W Equipment Leasing Inc; 1985-09-01 to 1987-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Michael C  Faykus → Spruce Run Surface Mine; 1986-02-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Prosperity Energy Inc → Spruce Run Surface Mine; 1987-06-05 to 1990-03-07; source msha-controller-operator-history
- **controller_controls_operator:** Michael C  Faykus → Prosperity Energy Inc; 1987-06-05 to 1990-03-07; source msha-controller-operator-history
- **controller_controls_mine:** Jack L  Williams → Spruce Run Surface Mine; 1988-02-24 to 1990-10-17; source msha-controller-operator-history
- **operator_operates_mine:** Nix Mining Company → Spruce Run Surface Mine; 1990-03-08 to 1990-10-17; source msha-controller-operator-history
- **controller_controls_operator:** Jack L  Williams → Nix Mining Company; 1990-03-08 to 1990-10-17; source msha-controller-operator-history
- **operator_operates_mine:** Nix Mining Company → Spruce Run Surface Mine; 1990-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Costain Group PLC → Spruce Run Surface Mine; 1990-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Costain Group PLC → Nix Mining Company; 1990-10-18 to current/open; source msha-controller-operator-history