# Relationship history for MSHA mine 0404114

Current hierarchy: **Steelhead Resources Ltd → Calspar Division-Steelhead Resources Inc → Calspar 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:** Descher Corp → Calspar Mine; 1950-01-01 to 1981-08-30; source msha-controller-operator-history
- **controller_controls_mine:** Descher Raymond J → Calspar Mine; 1950-01-01 to 1981-08-30; source msha-controller-operator-history
- **controller_controls_operator:** Descher Raymond J → Descher Corp; 1950-01-01 to 1981-08-30; source msha-controller-operator-history
- **operator_operates_mine:** Calspar Inc → Calspar Mine; 1981-08-31 to 1986-02-10; source msha-controller-operator-history
- **controller_controls_mine:** Industrial Mineral Products Inc → Calspar Mine; 1981-08-31 to 1986-02-10; source msha-controller-operator-history
- **controller_controls_operator:** Industrial Mineral Products Inc → Calspar Inc; 1981-08-31 to 1986-02-10; source msha-controller-operator-history
- **operator_operates_mine:** Calspar Division-Steelhead Resources Inc → Calspar Mine; 1986-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steelhead Resources Ltd → Calspar Mine; 1986-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steelhead Resources Ltd → Calspar Division-Steelhead Resources Inc; 1986-02-11 to current/open; source msha-controller-operator-history