# Relationship history for MSHA mine 0503883

Current hierarchy: **Risk Robert → Leadville Corp → Diamond Shaft**

- 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:** Christopherson Douglas → Diamond Shaft; 1982-04-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Leadville Corp → Diamond Shaft; 1983-08-01 to 1983-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Risk Robert → Diamond Shaft; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Risk Robert → Leadville Corp; 1983-08-01 to 1983-08-28; source msha-controller-operator-history
- **operator_operates_mine:** C & S Mining Company → Diamond Shaft; 1983-08-29 to 1986-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Christopherson Douglas → C & S Mining Company; 1983-08-29 to 1986-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Leadville Corp → Diamond Shaft; 1987-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Risk Robert → Leadville Corp; 1987-01-01 to current/open; source msha-controller-operator-history