# Relationship history for MSHA mine 4001172

Current hierarchy: **Studer Dale F & Paul J → Sequatchie Valley Coal Corp-Walden Ridge Div → No 1 Strip**

- 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:** Studer Dale F & Paul J → No 1 Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A B C D Coal Corp → No 1 Strip; 1972-01-01 to 1974-07-17; source msha-controller-operator-history
- **controller_controls_mine:** A B C D Coal Corp → No 1 Strip; 1972-01-01 to 1974-07-17; source msha-controller-operator-history
- **controller_controls_operator:** A B C D Coal Corp → A B C D Coal Corp; 1972-01-01 to 1974-07-17; source msha-controller-operator-history
- **operator_operates_mine:** Sequatchie Valley Coal Corp-Walden Ridge Div → No 1 Strip; 1974-07-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Studer Dale F & Paul J → Sequatchie Valley Coal Corp-Walden Ridge Div; 1974-07-18 to current/open; source msha-controller-operator-history