# Relationship history for MSHA mine 0503043

Current hierarchy: **North Fork Energy Corp - Hawk Mining Inc → Blue Ribbon Coal Company → Blue Ribbon**

- 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:** Sunflower Energy Corp → Blue Ribbon; 1977-04-01 to 1981-05-19; source msha-controller-operator-history
- **controller_controls_mine:** Asher James D → Blue Ribbon; 1977-04-01 to 1981-05-19; source msha-controller-operator-history
- **controller_controls_operator:** Asher James D → Sunflower Energy Corp; 1977-04-01 to 1981-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Blue Ribbon Coal Company → Blue Ribbon; 1981-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** North Fork Energy Corp - Hawk Mining Inc Et Al → Blue Ribbon; 1981-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** North Fork Energy Corp - Hawk Mining Inc Et Al → Blue Ribbon Coal Company; 1981-05-20 to current/open; source msha-controller-operator-history