# Relationship history for MSHA mine 0101679

Current hierarchy: **Mc Donald John F → Pleasant Grove Reclamation Project Inc → Project No 1**

- 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:** Energon Processing Corp → Project No 1; 1977-03-01 to 1977-07-19; source msha-controller-operator-history
- **controller_controls_mine:** Energon Companies Inc → Project No 1; 1977-03-01 to 1977-07-19; source msha-controller-operator-history
- **controller_controls_operator:** Energon Companies Inc → Energon Processing Corp; 1977-03-01 to 1977-07-19; source msha-controller-operator-history
- **operator_operates_mine:** Pleasant Grove Reclamation Project Inc → Project No 1; 1977-07-20 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Ashcraft Thomas F → Project No 1; 1977-07-20 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Ashcraft Thomas F → Pleasant Grove Reclamation Project Inc; 1977-07-20 to 1979-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Pleasant Grove Reclamation Project Inc → Project No 1; 1979-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Donald John F → Project No 1; 1979-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Donald John F → Pleasant Grove Reclamation Project Inc; 1979-09-01 to current/open; source msha-controller-operator-history