# Relationship history for MSHA mine 1510174

Current hierarchy: **Placer Dome Inc → Placer Coal Inc → Elliott No 4 Surface 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

- **controller_controls_mine:** Dehart Virgil Et Al → Elliott No 4 Surface Mine; 1975-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D D & S Coal Company → Elliott No 4 Surface Mine; 1977-01-01 to 1978-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Dehart Virgil Et Al → D D & S Coal Company; 1977-01-01 to 1978-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Placer Dome Inc → Elliott No 4 Surface Mine; 1978-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Placer Coal Inc → Elliott No 4 Surface Mine; 1978-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Placer Dome Inc → Placer Coal Inc; 1978-04-01 to current/open; source msha-controller-operator-history