# Relationship history for MSHA mine 4201501

Current hierarchy: **Nielsons Holding Company → Nielsons Inc → El Jay Double Cone**

- 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

- **controller_controls_mine:** Ashland Inc → El Jay Double Cone; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Peter Kiewit Sons' Inc → El Jay Double Cone; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Nielsons Holding Company → El Jay Double Cone; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Nielsons Inc → El Jay Double Cone; 1978-03-09 to 1979-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → Nielsons Inc; 1978-03-09 to 1979-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Peter Kiewit Sons' Company → El Jay Double Cone; 1979-11-01 to 1985-08-15; source msha-controller-operator-history
- **controller_controls_operator:** Peter Kiewit Sons' Inc → Peter Kiewit Sons' Company; 1979-11-01 to 1985-08-15; source msha-controller-operator-history
- **operator_operates_mine:** Nielsons Inc → El Jay Double Cone; 1985-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nielsons Holding Company → Nielsons Inc; 1985-08-16 to current/open; source msha-controller-operator-history