# Relationship history for MSHA mine 1510631

Current hierarchy: **Fields Bill & Archie Short → A & B Coal Company → No 2 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:** Sizemore Coal Company → No 2 Mine; 1977-08-01 to 1977-10-05; source msha-controller-operator-history
- **controller_controls_mine:** Sizemore James E-Franklin W Clark & Roger Tyler → No 2 Mine; 1977-08-01 to 1977-10-05; source msha-controller-operator-history
- **controller_controls_operator:** Sizemore James E-Franklin W Clark & Roger Tyler → Sizemore Coal Company; 1977-08-01 to 1977-10-05; source msha-controller-operator-history
- **operator_operates_mine:** Adams Coal Company → No 2 Mine; 1977-10-06 to 1978-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Brad Adams → No 2 Mine; 1977-10-06 to 1978-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Brad Adams → Adams Coal Company; 1977-10-06 to 1978-04-23; source msha-controller-operator-history
- **operator_operates_mine:** A & B Coal Company → No 2 Mine; 1978-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fields Bill & Archie Short → No 2 Mine; 1978-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fields Bill & Archie Short → A & B Coal Company; 1978-04-24 to current/open; source msha-controller-operator-history