# Relationship history for MSHA mine 1510061

Current hierarchy: **Ibex Inc → Kentucky Gem Coal Company-A Joint Venture → Kentucky Gem Tipple**

- 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:** Ibex Inc Et Al → Kentucky Gem Tipple; 1976-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kentucky Gem Coal Company-A Joint Venture → Kentucky Gem Tipple; 1976-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ibex Inc Et Al → Kentucky Gem Coal Company-A Joint Venture; 1976-11-01 to current/open; source msha-controller-operator-history