# Relationship history for MSHA mine 3606160

Current hierarchy: **Knorr Wallace → Lady Luck Coal Company → No 1 Slope**

- 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:** M & M Coal Company → No 1 Slope; 1976-07-20 to 1977-02-20; source msha-controller-operator-history
- **controller_controls_mine:** Berry Alfred J C--Irvin R & Walter E Maurer → No 1 Slope; 1976-07-20 to 1977-02-20; source msha-controller-operator-history
- **controller_controls_operator:** Berry Alfred J C--Irvin R & Walter E Maurer → M & M Coal Company; 1976-07-20 to 1977-02-20; source msha-controller-operator-history
- **controller_controls_mine:** Dennis  Snyder → No 1 Slope; 1976-10-23 to 2005-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Snyder Coal Company → No 1 Slope; 1977-02-21 to 1981-01-15; source msha-controller-operator-history
- **controller_controls_operator:** Dennis  Snyder → Snyder Coal Company; 1977-02-21 to 1981-01-15; source msha-controller-operator-history
- **operator_operates_mine:** Lady Luck Coal Company → No 1 Slope; 1981-01-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Knorr Wallace Et Al → No 1 Slope; 1981-01-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knorr Wallace Et Al → Lady Luck Coal Company; 1981-01-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis K  Snyder II → No 1 Slope; 2005-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis K  Snyder II → Snyder Coal Company; 2005-09-01 to 1981-01-15; source msha-controller-operator-history