# Relationship history for MSHA mine 1509709

Current hierarchy: **Fields Bill & Archie Short → A & B Coal Company → No 3 Mine**

- 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:** Three Way Coal Company → No 3 Mine; 1976-05-19 to 1976-10-06; source msha-controller-operator-history
- **controller_controls_mine:** Sandlin Daniel → No 3 Mine; 1976-05-19 to 1976-10-06; source msha-controller-operator-history
- **controller_controls_operator:** Sandlin Daniel → Three Way Coal Company; 1976-05-19 to 1976-10-06; source msha-controller-operator-history
- **operator_operates_mine:** Three Way Coal Company → No 3 Mine; 1976-10-07 to 1977-05-22; source msha-controller-operator-history
- **controller_controls_mine:** Adams Larry Dean → No 3 Mine; 1976-10-07 to 1977-05-22; source msha-controller-operator-history
- **controller_controls_operator:** Adams Larry Dean → Three Way Coal Company; 1976-10-07 to 1977-05-22; source msha-controller-operator-history
- **operator_operates_mine:** Explorer Coal Company Inc → No 3 Mine; 1977-05-23 to 1978-05-14; source msha-controller-operator-history
- **controller_controls_mine:** Richmond Clifford Jr → No 3 Mine; 1977-05-23 to 1978-05-14; source msha-controller-operator-history
- **controller_controls_operator:** Richmond Clifford Jr → Explorer Coal Company Inc; 1977-05-23 to 1978-05-14; source msha-controller-operator-history
- **controller_controls_mine:** Fields Bill & Archie Short → No 3 Mine; 1978-04-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A & B Coal Company → No 3 Mine; 1978-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fields Bill & Archie Short → A & B Coal Company; 1978-05-15 to current/open; source msha-controller-operator-history