# Relationship history for MSHA mine 1507274

Current hierarchy: **Potter A C → Ace Mining Corp → 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:** Looney & Fields Coal Company Inc → No 2 Mine; 1974-08-19 to 1975-01-06; source msha-controller-operator-history
- **controller_controls_mine:** Looney Ron K & Gary Fields → No 2 Mine; 1974-08-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Looney Ron K & Gary Fields → Looney & Fields Coal Company Inc; 1974-08-19 to 1975-01-06; source msha-controller-operator-history
- **operator_operates_mine:** Ace Mining Corp → No 2 Mine; 1975-01-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Potter A C → No 2 Mine; 1975-01-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Potter A C → Ace Mining Corp; 1975-01-07 to current/open; source msha-controller-operator-history