# Relationship history for MSHA mine 2901847

Current hierarchy: **John L  Ary → A & S Construction Company Of New Mexico Inc → 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Kent Nowlin Inc → Crusher #1; 1980-12-01 to 1986-05-12; source msha-controller-operator-history
- **controller_controls_mine:** Nowlin Kent → Crusher #1; 1980-12-01 to 1986-05-12; source msha-controller-operator-history
- **controller_controls_operator:** Nowlin Kent → Kent Nowlin Inc; 1980-12-01 to 1986-05-12; source msha-controller-operator-history
- **operator_operates_mine:** A & S Construction Company Of New Mexico Inc → Crusher #1; 1986-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John L  Ary → Crusher #1; 1986-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John L  Ary → A & S Construction Company Of New Mexico Inc; 1986-05-13 to current/open; source msha-controller-operator-history