# Relationship history for MSHA mine 3303307

Current hierarchy: **James F  Graham → Swan Coal Company → Swan No 1 Strip**

- 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:** Swan Coal Company → Swan No 1 Strip; 1975-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James F  Graham → Swan No 1 Strip; 1975-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James F  Graham → Swan Coal Company; 1975-04-01 to current/open; source msha-controller-operator-history