# Relationship history for MSHA mine 4605897

Current hierarchy: **Shaw G T → F S & P Coal Company Inc → Swiss No 1 Surface**

- 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:** Wymer William O → Swiss No 1 Surface; 1977-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wyett Mines Inc → Swiss No 1 Surface; 1978-11-01 to 1979-04-15; source msha-controller-operator-history
- **controller_controls_operator:** Wymer William O → Wyett Mines Inc; 1978-11-01 to 1979-04-15; source msha-controller-operator-history
- **operator_operates_mine:** F S & P Coal Company Inc → Swiss No 1 Surface; 1979-04-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shaw G T → Swiss No 1 Surface; 1979-04-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shaw G T → F S & P Coal Company Inc; 1979-04-16 to current/open; source msha-controller-operator-history