# Relationship history for MSHA mine 4001858

Current hierarchy: **Welch Lester Sr → Kay Fabe Coal Co → 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

- **operator_operates_mine:** Kay Fabe Coal Co → No 1 Surface; 1975-01-01 to 1975-09-29; source msha-controller-operator-history
- **controller_controls_mine:** Welch Lester Sr → No 1 Surface; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Welch Lester Sr → Kay Fabe Coal Co; 1975-01-01 to 1975-09-29; source msha-controller-operator-history
- **operator_operates_mine:** Allardt Coal Company Inc → No 1 Surface; 1975-09-30 to 1977-02-10; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Robert C → No 1 Surface; 1975-09-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Robert C → Allardt Coal Company Inc; 1975-09-30 to 1977-02-10; source msha-controller-operator-history
- **operator_operates_mine:** Kay Fabe Coal Co → No 1 Surface; 1977-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Welch Lester Sr → Kay Fabe Coal Co; 1977-02-11 to current/open; source msha-controller-operator-history