# Relationship history for MSHA mine 1001838

Current hierarchy: **Leroy  Howell → Leroy Howell → Portable**

- 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:** Welch'S Rock → Portable; 1988-09-01 to 1998-04-07; source msha-controller-operator-history
- **controller_controls_mine:** Abie O  Welch → Portable; 1988-09-01 to 1998-04-07; source msha-controller-operator-history
- **controller_controls_operator:** Abie O  Welch → Welch'S Rock; 1988-09-01 to 1998-04-07; source msha-controller-operator-history
- **operator_operates_mine:** Wmc Rock → Portable; 1998-04-08 to 2000-05-16; source msha-controller-operator-history
- **controller_controls_mine:** Warren E  Meisner → Portable; 1998-04-08 to 2000-05-16; source msha-controller-operator-history
- **controller_controls_operator:** Warren E  Meisner → Wmc Rock; 1998-04-08 to 2000-05-16; source msha-controller-operator-history
- **operator_operates_mine:** Leroy Howell → Portable; 2000-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Leroy  Howell → Portable; 2000-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leroy  Howell → Leroy Howell; 2000-05-17 to current/open; source msha-controller-operator-history