# Relationship history for MSHA mine 4101130

Current hierarchy: **Cemex S A → Sunbelt Asphalt & Materials Inc → Echo Ii Sand Dredge**

- 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:** Parker Brothers & Company Inc → Echo Ii Sand Dredge; 1950-01-01 to 1990-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Robert H Parker et al → Echo Ii Sand Dredge; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H Parker et al → Parker Brothers & Company Inc; 1950-01-01 to 1990-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Briscoe K Parker Jr et al → Parker Brothers & Company Inc; 1950-01-01 to 1990-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Parker Lafarge Inc → Echo Ii Sand Dredge; 1990-06-01 to 1994-09-08; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge Coppee & Parker Lafarge Inc → Echo Ii Sand Dredge; 1990-06-01 to 1994-09-08; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge Coppee & Parker Lafarge Inc → Parker Lafarge Inc; 1990-06-01 to 1994-09-08; source msha-controller-operator-history
- **operator_operates_mine:** Sunbelt Asphalt & Materials Inc → Echo Ii Sand Dredge; 1994-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → Echo Ii Sand Dredge; 1994-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → Sunbelt Asphalt & Materials Inc; 1994-09-09 to current/open; source msha-controller-operator-history