# Relationship history for MSHA mine 0501009

Current hierarchy: **Pfaffenhauser Raymond → Pfaffenhauser Construction → Portable Crusher**

- 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:** Huerfano Peak Sand & Gravel Inc → Portable Crusher; 1950-01-01 to 1982-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Mc Dougal Glen → Portable Crusher; 1950-01-01 to 1982-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Mc Dougal Glen → Huerfano Peak Sand & Gravel Inc; 1950-01-01 to 1982-08-09; source msha-controller-operator-history
- **operator_operates_mine:** R-J Graham Inc → Portable Crusher; 1982-08-10 to 1983-10-26; source msha-controller-operator-history
- **controller_controls_mine:** Graham John R & Roger F → Portable Crusher; 1982-08-10 to 1983-10-26; source msha-controller-operator-history
- **controller_controls_operator:** Graham John R & Roger F → R-J Graham Inc; 1982-08-10 to 1983-10-26; source msha-controller-operator-history
- **operator_operates_mine:** Pfaffenhauser Construction → Portable Crusher; 1983-10-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pfaffenhauser Raymond → Portable Crusher; 1983-10-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pfaffenhauser Raymond → Pfaffenhauser Construction; 1983-10-27 to current/open; source msha-controller-operator-history