# Relationship history for MSHA mine 4000187

Current hierarchy: **Ranchers Exploration & Development Corp → Kentucky-Tennessee Clay Company → Bell Mill**

- 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:** Kentucky-Tennessee Clay Company → Bell Mill; 1950-01-01 to 1983-03-28; source msha-controller-operator-history
- **controller_controls_mine:** Chester  Gulick → Bell Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chester  Gulick → Kentucky-Tennessee Clay Company; 1950-01-01 to 1983-03-28; source msha-controller-operator-history
- **operator_operates_mine:** Kentucky-Tennessee Clay Company → Bell Mill; 1983-03-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ranchers Exploration & Development Corp → Bell Mill; 1983-03-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ranchers Exploration & Development Corp → Kentucky-Tennessee Clay Company; 1983-03-29 to current/open; source msha-controller-operator-history