# Relationship history for MSHA mine 4607782

Current hierarchy: **Delmer S  Vencill → Vencill Corp → Ramp Run 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:** Tim Doug  Johnson → Ramp Run Surface Mine; 1984-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Delmer S  Vencill → Ramp Run Surface Mine; 1987-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Chloe Ridge Coal Company Inc → Ramp Run Surface Mine; 1989-10-01 to 1991-02-19; source msha-controller-operator-history
- **controller_controls_operator:** Tim Doug  Johnson → Chloe Ridge Coal Company Inc; 1989-10-01 to 1991-02-19; source msha-controller-operator-history
- **operator_operates_mine:** Vencill Corp → Ramp Run Surface Mine; 1991-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Delmer S  Vencill → Vencill Corp; 1991-02-20 to current/open; source msha-controller-operator-history