# Relationship history for MSHA mine 4800529

Current hierarchy: **Eagle Materials Inc → Mountain Cement Company LLC → Portable Crusher #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:** Wyoming Construction Company → Portable Crusher #1; 1950-01-01 to 1986-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Monolith Portland Cement Company → Portable Crusher #1; 1950-01-01 to 1986-01-26; source msha-controller-operator-history
- **controller_controls_operator:** Monolith Portland Cement Company → Wyoming Construction Company; 1950-01-01 to 1986-01-26; source msha-controller-operator-history
- **operator_operates_mine:** Mountain Cement Company LLC → Portable Crusher #1; 1986-01-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eagle Materials Inc → Portable Crusher #1; 1986-01-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eagle Materials Inc → Mountain Cement Company LLC; 1986-01-27 to current/open; source msha-controller-operator-history