# Relationship history for MSHA mine 0404651

Current hierarchy: **Helms Robert L Construction & Development Co → Lost Dutchman Construction Inc → Snowcap Mine**

- 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:** Eagle-Picher Industries Inc → Snowcap Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eagle-Picher Industries Inc → Snowcap Mine; 1983-07-01 to 1987-03-11; source msha-controller-operator-history
- **controller_controls_operator:** Eagle-Picher Industries Inc → Eagle-Picher Industries Inc; 1983-07-01 to 1987-03-11; source msha-controller-operator-history
- **controller_controls_mine:** Helms Robert L Construction & Development Co → Snowcap Mine; 1986-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lost Dutchman Construction Inc → Snowcap Mine; 1987-03-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Helms Robert L Construction & Development Co → Lost Dutchman Construction Inc; 1987-03-12 to current/open; source msha-controller-operator-history