# Relationship history for MSHA mine 1300655

Current hierarchy: **Valley Corp → Builders Sand & Cement Company → Floating 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:** Builders Sand & Gravel Company → Floating Dredge; 1950-01-01 to 1981-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Delarue E → Floating Dredge; 1950-01-01 to 1981-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Delarue E → Builders Sand & Gravel Company; 1950-01-01 to 1981-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Builders Sand & Cement Company → Floating Dredge; 1981-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Valley Corp → Floating Dredge; 1981-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Valley Corp → Builders Sand & Cement Company; 1981-03-01 to current/open; source msha-controller-operator-history