# Relationship history for MSHA mine 4200023

Current hierarchy: **Lon  A  Thomas → American Stone Company → Aragonite**

- 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:** Utah Calcium Company Inc → Aragonite; 1950-01-01 to 1987-08-25; source msha-controller-operator-history
- **controller_controls_mine:** Lon  A  Thomas → Aragonite; 1950-01-01 to 1987-08-25; source msha-controller-operator-history
- **controller_controls_operator:** Lon  A  Thomas → Utah Calcium Company Inc; 1950-01-01 to 1987-08-25; source msha-controller-operator-history
- **controller_controls_mine:** Lon  A  Thomas → Aragonite; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Utah Calcium Company → Aragonite; 1987-08-26 to 1988-04-07; source msha-controller-operator-history
- **controller_controls_mine:** Harapiak Steve → Aragonite; 1987-08-26 to 1988-04-07; source msha-controller-operator-history
- **controller_controls_operator:** Harapiak Steve → Utah Calcium Company; 1987-08-26 to 1988-04-07; source msha-controller-operator-history
- **operator_operates_mine:** Utah Calcium Company → Aragonite; 1988-04-08 to 1988-11-14; source msha-controller-operator-history
- **controller_controls_mine:** White Rick W → Aragonite; 1988-04-08 to 1988-11-14; source msha-controller-operator-history
- **controller_controls_operator:** White Rick W → Utah Calcium Company; 1988-04-08 to 1988-11-14; source msha-controller-operator-history
- **operator_operates_mine:** American Stone Company → Aragonite; 1988-11-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lon  A  Thomas → American Stone Company; 1988-11-15 to current/open; source msha-controller-operator-history