# Relationship history for MSHA mine 4605453

Current hierarchy: **Bjorkman Joseph O → Point Coal Company → Barlow #2**

- 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:** Point Coal Company → Barlow #2; 1977-01-01 to 1980-09-03; source msha-controller-operator-history
- **controller_controls_mine:** Laurita James L-Rocky Marko Et Al → Barlow #2; 1977-01-01 to 1980-09-03; source msha-controller-operator-history
- **controller_controls_operator:** Laurita James L-Rocky Marko Et Al → Point Coal Company; 1977-01-01 to 1980-09-03; source msha-controller-operator-history
- **operator_operates_mine:** Point Coal Company → Barlow #2; 1980-09-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bjorkman Joseph O → Barlow #2; 1980-09-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bjorkman Joseph O → Point Coal Company; 1980-09-04 to current/open; source msha-controller-operator-history