# Relationship history for MSHA mine 4406446

Current hierarchy: **Gary  Baker → Ivy Branch Coal Company Inc → No 19**

- 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

- **operator_operates_mine:** Big Caney Contractors Inc → No 19; 1988-03-01 to 1990-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Barton Delmar → No 19; 1988-03-01 to 1990-07-10; source msha-controller-operator-history
- **controller_controls_operator:** Barton Delmar → Big Caney Contractors Inc; 1988-03-01 to 1990-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Charles H  Gent → No 19; 1988-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary  Baker → No 19; 1990-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H B & B Equipment Company Inc → No 19; 1990-07-11 to 1992-04-13; source msha-controller-operator-history
- **controller_controls_operator:** Charles H  Gent → H B & B Equipment Company Inc; 1990-07-11 to 1992-04-13; source msha-controller-operator-history
- **operator_operates_mine:** Ivy Branch Coal Company Inc → No 19; 1992-04-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Baker → Ivy Branch Coal Company Inc; 1992-04-14 to current/open; source msha-controller-operator-history