# Relationship history for MSHA mine 3606991

Current hierarchy: **Swistock James W → Swistock Associates Coal Corp → Cambria County**

- 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:** Swistock James W → Cambria County; 1978-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Swistock Associates Coal Corp → Cambria County; 1980-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Swistock James W → Swistock Associates Coal Corp; 1980-06-01 to current/open; source msha-controller-operator-history