# Relationship history for MSHA mine 1513213

Current hierarchy: **Infinity Coal Corp → Hickory Hill Development Corp → Mill Branch Mine**

- 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

- **controller_controls_mine:** Central Kentucky Landscaping Company → Mill Branch Mine; 1976-04-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ultra Energy Corp → Mill Branch Mine; 1981-11-01 to 1983-10-10; source msha-controller-operator-history
- **controller_controls_mine:** Damron Roger → Mill Branch Mine; 1981-11-01 to 1983-10-10; source msha-controller-operator-history
- **controller_controls_operator:** Damron Roger → Ultra Energy Corp; 1981-11-01 to 1983-10-10; source msha-controller-operator-history
- **operator_operates_mine:** L T Ruth Coal Company Inc → Mill Branch Mine; 1983-10-11 to 1990-05-28; source msha-controller-operator-history
- **controller_controls_operator:** Central Kentucky Landscaping Company → L T Ruth Coal Company Inc; 1983-10-11 to 1990-05-28; source msha-controller-operator-history
- **controller_controls_mine:** Infinity Coal Corp → Mill Branch Mine; 1989-03-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hickory Hill Development Corp → Mill Branch Mine; 1990-05-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Infinity Coal Corp → Hickory Hill Development Corp; 1990-05-29 to current/open; source msha-controller-operator-history