# Relationship history for MSHA mine 4103831

Current hierarchy: **Edwin E  Forshage III → Frontera Materials Inc → MOBILE CRUSHER #2**

- 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:** Edwin E  Forshage III  et al → MOBILE CRUSHER #2; 1985-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Frontera Materials Inc → MOBILE CRUSHER #2; 1994-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edwin E  Forshage III  et al → Frontera Materials Inc; 1994-09-01 to current/open; source msha-controller-operator-history