# Relationship history for MSHA mine 1700144

Current hierarchy: **Lawrence  Grondin → R J Grondin & Sons → Leroy Prout Pit And Mill**

- 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:** Leroy S Prout Sand & Gravel → Leroy Prout Pit And Mill; 1950-01-01 to 1980-02-05; source msha-controller-operator-history
- **controller_controls_mine:** Risbara Rocco C → Leroy Prout Pit And Mill; 1950-01-01 to 1980-02-05; source msha-controller-operator-history
- **controller_controls_operator:** Risbara Rocco C → Leroy S Prout Sand & Gravel; 1950-01-01 to 1980-02-05; source msha-controller-operator-history
- **controller_controls_mine:** Robert J  Grondin et al → Leroy Prout Pit And Mill; 1979-12-01 to 2015-09-30; source msha-controller-operator-history
- **operator_operates_mine:** R J Grondin & Sons → Leroy Prout Pit And Mill; 1980-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert J  Grondin et al → R J Grondin & Sons; 1980-02-06 to 2015-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth J  Grondin et al → R J Grondin & Sons; 1980-02-06 to 2015-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Philip H Grondin Jr et al → Leroy Prout Pit And Mill; 2015-10-01 to 2022-11-08; source msha-controller-operator-history
- **controller_controls_operator:** Philip H Grondin Jr et al → R J Grondin & Sons; 2015-10-01 to 2022-11-08; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence  Grondin et al → R J Grondin & Sons; 2015-10-01 to 2022-11-08; source msha-controller-operator-history
- **controller_controls_mine:** Lawrence  Grondin et al → Leroy Prout Pit And Mill; 2022-11-09 to 2023-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence  Grondin et al → R J Grondin & Sons; 2022-11-09 to 2023-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Grondin III et al → R J Grondin & Sons; 2022-11-09 to 2023-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Lawrence  Grondin → Leroy Prout Pit And Mill; 2024-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence  Grondin → R J Grondin & Sons; 2024-01-01 to current/open; source msha-controller-operator-history