# Relationship history for MSHA mine 1516578

Current hierarchy: **Philips James L → Al-Co Mining Inc → #1**

- 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:** Al-Co Mining Inc → #1; 1989-03-01 to 1991-08-05; source msha-controller-operator-history
- **controller_controls_mine:** Ledford Curtis → #1; 1989-03-01 to 1991-08-05; source msha-controller-operator-history
- **controller_controls_operator:** Ledford Curtis → Al-Co Mining Inc; 1989-03-01 to 1991-08-05; source msha-controller-operator-history
- **operator_operates_mine:** Al-Co Mining Inc → #1; 1991-08-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Philips James L → #1; 1991-08-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Philips James L → Al-Co Mining Inc; 1991-08-06 to current/open; source msha-controller-operator-history