# Relationship history for MSHA mine 1102928

Current hierarchy: **Daniele R  Sproule → Sproule Construction Co.,Inc. → PORTABLE NO. 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:** W C Stewart Construction Inc → PORTABLE NO. 1; 1992-08-01 to 1994-08-30; source msha-controller-operator-history
- **controller_controls_mine:** Wayne C  Stewart → PORTABLE NO. 1; 1992-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wayne C  Stewart → W C Stewart Construction Inc; 1992-08-01 to 1994-08-30; source msha-controller-operator-history
- **operator_operates_mine:** Sproule Construction Company Inc → PORTABLE NO. 1; 1994-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Daniele R  Sproule et al → PORTABLE NO. 1; 1994-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniele R  Sproule et al → Sproule Construction Company Inc; 1994-08-31 to current/open; source msha-controller-operator-history