# Relationship history for MSHA mine 3500521

Current hierarchy: **Knife River Corporation → Knife River Corporation-Northwest → STAYTON ROCK PIT**

- 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:** Morse Brothers Inc → STAYTON ROCK PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** North Santiam Sand & Gravel Inc → STAYTON ROCK PIT; 1950-01-01 to 1987-05-26; source msha-controller-operator-history
- **controller_controls_mine:** Francis  Lulay → STAYTON ROCK PIT; 1950-01-01 to 1987-05-26; source msha-controller-operator-history
- **controller_controls_operator:** Francis  Lulay → North Santiam Sand & Gravel Inc; 1950-01-01 to 1987-05-26; source msha-controller-operator-history
- **operator_operates_mine:** Stayton Rock Products Inc → STAYTON ROCK PIT; 1987-05-27 to 1994-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Robert M  Beil → STAYTON ROCK PIT; 1987-05-27 to 1994-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Robert M  Beil → Stayton Rock Products Inc; 1987-05-27 to 1994-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Morse Brothers Inc → STAYTON ROCK PIT; 1994-05-01 to 1998-03-04; source msha-controller-operator-history
- **controller_controls_operator:** Morse Brothers Inc → Morse Brothers Inc; 1994-05-01 to 1998-03-04; source msha-controller-operator-history
- **operator_operates_mine:** Knife River Corporation-Northwest → STAYTON ROCK PIT; 1998-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → STAYTON ROCK PIT; 1998-03-05 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Knife River Corporation-Northwest; 1998-03-05 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → STAYTON ROCK PIT; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River Corporation-Northwest; 2023-06-01 to current/open; source msha-controller-operator-history