# Relationship history for MSHA mine 2900341

Current hierarchy: **Graves David R → Rico Mining Company Inc → Bearup 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:** U S Spirit Corp → Bearup Mine; 1950-01-01 to 1991-07-06; source msha-controller-operator-history
- **controller_controls_mine:** Riebold E M → Bearup Mine; 1950-01-01 to 1991-07-06; source msha-controller-operator-history
- **controller_controls_operator:** Riebold E M → U S Spirit Corp; 1950-01-01 to 1991-07-06; source msha-controller-operator-history
- **operator_operates_mine:** Rico Mining Company Inc → Bearup Mine; 1991-07-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Graves David R → Bearup Mine; 1991-07-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graves David R → Rico Mining Company Inc; 1991-07-07 to current/open; source msha-controller-operator-history