# Relationship history for MSHA mine 2600906

Current hierarchy: **Archer Kenneth B → Modoc Mining Company → Fallon 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Standard Slag Company → Fallon Mill; 1950-01-01 to 1987-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Standard Slag Company → Fallon Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Standard Slag Company → Standard Slag Company; 1950-01-01 to 1987-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Standard Magnesia Company → Fallon Mill; 1987-09-01 to 1989-01-16; source msha-controller-operator-history
- **controller_controls_mine:** Richard B  Harmon et al → Fallon Mill; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard B  Harmon et al → Standard Magnesia Company; 1987-09-01 to 1989-01-16; source msha-controller-operator-history
- **operator_operates_mine:** Modoc Mining Company → Fallon Mill; 1989-01-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Archer Kenneth B → Fallon Mill; 1989-01-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Archer Kenneth B → Modoc Mining Company; 1989-01-17 to current/open; source msha-controller-operator-history