# Relationship history for MSHA mine 4404942

Current hierarchy: **Shortridge Keaster → Q & G Coal Company Inc → No 19 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:** Shortridge Keaster Et Al → No 19 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Q & G Coal Company Inc → No 19 Mine; 1978-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shortridge Keaster Et Al → Q & G Coal Company Inc; 1978-01-01 to current/open; source msha-controller-operator-history