# Relationship history for MSHA mine 3601860

Current hierarchy: **Lucas Gary → Lucas & Partners Coal Company → Tracy 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:** Herring Bros & Lucas Coal Company → Tracy Slope; 1950-01-01 to 1977-03-27; source msha-controller-operator-history
- **controller_controls_mine:** Lucas Ray & Lester Herring → Tracy Slope; 1950-01-01 to 1977-03-27; source msha-controller-operator-history
- **controller_controls_operator:** Lucas Ray & Lester Herring → Herring Bros & Lucas Coal Company; 1950-01-01 to 1977-03-27; source msha-controller-operator-history
- **operator_operates_mine:** Lucas & Partners Coal Company → Tracy Slope; 1977-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lucas Gary Et Al → Tracy Slope; 1977-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lucas Gary Et Al → Lucas & Partners Coal Company; 1977-03-28 to current/open; source msha-controller-operator-history