# Relationship history for MSHA mine 4607733

Current hierarchy: **Mc Kinney Carlton Jr → Bull Run Mining Company Inc → Frontier 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:** Mc Kinney Carlton Jr → Frontier Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** FSS Coal Holding Inc → Frontier Mine; 1985-10-18 to 1992-01-14; source msha-controller-operator-history
- **operator_operates_mine:** Kingwood Mining Company → Frontier Mine; 1989-07-01 to 1990-01-29; source msha-controller-operator-history
- **controller_controls_operator:** FSS Coal Holding Inc → Kingwood Mining Company; 1989-07-01 to 1990-01-29; source msha-controller-operator-history
- **operator_operates_mine:** Bull Run Mining Company Inc → Frontier Mine; 1990-01-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Kinney Carlton Jr → Bull Run Mining Company Inc; 1990-01-30 to current/open; source msha-controller-operator-history