# Relationship history for MSHA mine 2601894

Current hierarchy: **Ayres William D & R Watson → Graystone Minerals Corp → B & M Placer 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

- **operator_operates_mine:** Spoonemore Construction → B & M Placer Mine; 1984-07-01 to 1984-12-12; source msha-controller-operator-history
- **controller_controls_mine:** Spoonemore Ford → B & M Placer Mine; 1984-07-01 to 1984-12-12; source msha-controller-operator-history
- **controller_controls_operator:** Spoonemore Ford → Spoonemore Construction; 1984-07-01 to 1984-12-12; source msha-controller-operator-history
- **operator_operates_mine:** Graystone Minerals Corp → B & M Placer Mine; 1984-12-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ayres William D & R Watson → B & M Placer Mine; 1984-12-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ayres William D & R Watson → Graystone Minerals Corp; 1984-12-13 to current/open; source msha-controller-operator-history