# Relationship history for MSHA mine 1515532

Current hierarchy: **Merritt F M → Ashcamp Construction 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

- **controller_controls_mine:** Huston Hubert → #1; 1984-06-29 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sharp Coal Company Inc → #1; 1986-02-01 to 1987-07-26; source msha-controller-operator-history
- **controller_controls_operator:** Huston Hubert → Sharp Coal Company Inc; 1986-02-01 to 1987-07-26; source msha-controller-operator-history
- **operator_operates_mine:** Ashcamp Construction Inc → #1; 1987-07-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Merritt F M → #1; 1987-07-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Merritt F M → Ashcamp Construction Inc; 1987-07-27 to current/open; source msha-controller-operator-history