# Relationship history for MSHA mine 3301159

Current hierarchy: **ACNR Holdings, Inc → Ohio Valley Coal Resources, Inc. → Powhatan No. 6 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:** Nacco Mining Company → Powhatan No. 6 Mine; 1950-01-01 to 1988-05-24; source msha-controller-operator-history
- **controller_controls_mine:** NACCO Industries Inc → Powhatan No. 6 Mine; 1950-01-01 to 1988-05-24; source msha-controller-operator-history
- **controller_controls_operator:** NACCO Industries Inc → Nacco Mining Company; 1950-01-01 to 1988-05-24; source msha-controller-operator-history
- **operator_operates_mine:** Ohio Valley Coal Resources, Inc. → Powhatan No. 6 Mine; 1988-05-25 to 2020-09-16; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → Powhatan No. 6 Mine; 1988-05-25 to 2020-09-16; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Ohio Valley Coal Resources, Inc.; 1988-05-25 to 2020-09-16; source msha-controller-operator-history
- **operator_operates_mine:** Ohio Valley Coal Resources, Inc. → Powhatan No. 6 Mine; 2020-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** ACNR Holdings, Inc → Powhatan No. 6 Mine; 2020-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** ACNR Holdings, Inc → Ohio Valley Coal Resources, Inc.; 2020-09-17 to current/open; source msha-controller-operator-history