# Relationship history for MSHA mine 0504077

Current hierarchy: **Mikell L  Koellner → L & L Ready Mix → KOELLNER LEASED PITS**

- 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:** L & L Ready Mix → KOELLNER LEASED PITS; 1985-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mikell L  Koellner → KOELLNER LEASED PITS; 1985-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mikell L  Koellner → L & L Ready Mix; 1985-07-01 to current/open; source msha-controller-operator-history