# Relationship history for MSHA mine 0500299

Current hierarchy: **Tri-State Generation and Transmission Assn Inc → Elk Ridge Mining and Reclamation LLC → New Horizon 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:** Peabody Coal Company → New Horizon Mine; 1950-01-01 to 1977-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Kennecott Copper Corp → New Horizon Mine; 1950-01-01 to 1977-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Kennecott Copper Corp → Peabody Coal Company; 1950-01-01 to 1977-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → New Horizon Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Peabody Coal Company → New Horizon Mine; 1977-07-01 to 1992-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Peabody Coal Company; 1977-07-01 to 1992-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Elk Ridge Mining and Reclamation LLC → New Horizon Mine; 1992-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tri-State Generation & Transmission Assn Inc et al → New Horizon Mine; 1992-07-01 to 2016-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Tri-State Generation & Transmission Assn Inc et al → Elk Ridge Mining and Reclamation LLC; 1992-07-01 to 2016-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Western Fuels Assoc Inc et al → Elk Ridge Mining and Reclamation LLC; 1992-07-01 to 2016-06-07; source msha-controller-operator-history
- **controller_controls_mine:** Tri-State Generation and Transmission Assn Inc → New Horizon Mine; 2016-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tri-State Generation and Transmission Assn Inc → Elk Ridge Mining and Reclamation LLC; 2016-06-08 to current/open; source msha-controller-operator-history