# Relationship history for MSHA mine 1401536

Current hierarchy: **Dinkel Ralph → Wes-Kan Construction Inc → PORTABLE SAND PLANT #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:** Hays Asphalt Construction Inc → PORTABLE SAND PLANT #1; 1990-05-01 to 1997-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Rich  Dinkel et al → PORTABLE SAND PLANT #1; 1990-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rich  Dinkel et al → Hays Asphalt Construction Inc; 1990-05-01 to 1997-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Steve  Pfannenstiel et al → Hays Asphalt Construction Inc; 1990-05-01 to 1997-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Dinkel Ralph → PORTABLE SAND PLANT #1; 1994-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wes-Kan Construction Inc → PORTABLE SAND PLANT #1; 1997-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dinkel Ralph → Wes-Kan Construction Inc; 1997-10-01 to current/open; source msha-controller-operator-history