# Relationship history for MSHA mine 3601821

Current hierarchy: **Mace Dennis R → K M & K Coal Company → D + R 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:** D & R Coal Company → D + R Slope; 1950-01-01 to 1974-12-11; source msha-controller-operator-history
- **controller_controls_mine:** D & R Coal Co → D + R Slope; 1950-01-01 to 1974-12-11; source msha-controller-operator-history
- **controller_controls_operator:** D & R Coal Co → D & R Coal Company; 1950-01-01 to 1974-12-11; source msha-controller-operator-history
- **operator_operates_mine:** K M & K Coal Company → D + R Slope; 1974-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mace Dennis R Et Al → D + R Slope; 1974-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mace Dennis R Et Al → K M & K Coal Company; 1974-12-12 to current/open; source msha-controller-operator-history