# Relationship history for MSHA mine 1515760

Current hierarchy: **Ron  Newberry → Carbon Tech Fuels, Inc → No 1 Plant**

- 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:** Edco Energy Corp → No 1 Plant; 1986-09-01 to 1995-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Edward  Groves → No 1 Plant; 1986-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward  Groves → Edco Energy Corp; 1986-09-01 to 1995-02-27; source msha-controller-operator-history
- **operator_operates_mine:** Carbon Tech Fuels, Inc → No 1 Plant; 1995-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ron  Newberry → No 1 Plant; 1995-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ron  Newberry → Carbon Tech Fuels, Inc; 1995-02-28 to current/open; source msha-controller-operator-history