# Relationship history for MSHA mine 3400977

Current hierarchy: **Haugan D M → Tri-Con Limited → No 101 Strip**

- 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:** Tri-Con Limited → No 101 Strip; 1976-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Haugan D M → No 101 Strip; 1976-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Haugan D M → Tri-Con Limited; 1976-09-01 to current/open; source msha-controller-operator-history