# Relationship history for MSHA mine 3303330

Current hierarchy: **Mesmer Ted & Sons Inc → Ted Mesmer & Sons Inc → Dobson Road Pit (Strip) Ketchum**

- 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

- **controller_controls_mine:** Mesmer Ted & Sons Inc → Dobson Road Pit (Strip) Ketchum; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ted Mesmer & Sons Inc → Dobson Road Pit (Strip) Ketchum; 1975-05-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mesmer Ted & Sons Inc → Ted Mesmer & Sons Inc; 1975-05-30 to current/open; source msha-controller-operator-history