Mill River Union High School, commonly known as Mill River or MRU is a public junior-senior high school in Clarendon, Vermont, in the United States. It is part of the Mill River Unified Union School District. MRUUSD includes the towns of Clarendon, Wallingford, Shrewsbury and Tinmouth.
Serving 368 students in grades 7-12, Mill River Union High School ranks in the bottom 50% of all schools in Vermont for overall test scores (math proficiency is bottom 50%, and reading proficiency is bottom 50%).
The percentage of students achieving proficiency in math is 20-24% (which is lower than the Vermont state average of 40%). The percentage of students achieving proficiency in reading/language arts is 40-44% (which is approximately equal to the Vermont state average of 44%).
The student-teacher ratio of 9:1 is lower than the Vermont state level of 11:1.
Minority enrollment is 4% of the student body (majority Black and Hispanic), which is lower than the Vermont state average of 13% (majority Hispanic).
Quick Facts (2026)
- Grades: 7-12
- Enrollment: 368 students
- Student-Teacher Ratio: 9:1
- Minority Enrollment: 4%
- Graduation Rate: 75-79% (Btm 50% in VT)
- Overall Testing Rank: Bottom 50%
- Math Proficiency: 20-24% (Btm 50%)
- Reading Proficiency: 40-44% (Btm 50%)
- Science Proficiency: 25-29% (Btm 50%)
- Source: National Center for Education Statistics (NCES), VT Dept. of Education
School Overview
Mill River Union High School's student population of 368 students has declined by 6% over five school years.
The teacher population of 39 teachers has stayed relatively flat over five school years.
Grades Offered
Grades 7-12
(Supplemental Virtual)
(Supplemental Virtual)
Total Students
368 students
Total Classroom Teachers
39 teachers
Year Founded
1975
School Rankings
Mill River Union High School ranks within the bottom 50% of all 280 schools in Vermont (based off of combined math and reading proficiency testing data).
The diversity score of Mill River Union High School is 0.08, which is less than the diversity score at state average of 0.25. The school's diversity has stayed relatively flat over five school years.
Overall Testing Rank
#205 out of 280 schools
(Bottom 50%)
(Bottom 50%)
Math Test Scores (% Proficient)
20-24%
40%
Reading/Language Arts Test Scores (% Proficient)
40-44%
44%
Science Test Scores (% Proficient)
25-29%
35%
Student-Teacher Ratio
9:1
11:1
Hispanic
1%
4%
Black
1%
3%
White
96%
87%
Two or more races
2%
4%
All Ethnic Groups
Graduation Rate
75-79%
83%
Chronically Absent Students
(22-23)47.8%
27.8%
Eligible for Free Lunch
42%
38%
Eligible for Reduced Lunch
8%
9%
School Statewide Testing
School District Name
Source: National Center for Education Statistics (NCES), VT Dept. of Education
School Notes
- School Mascot: Minuteman
Frequently Asked Questions
What is Mill River Union High School's ranking?
Mill River Union High School is ranked #205 out of 280 schools, which ranks it among the bottom 50% of public schools in Vermont.
What schools are Mill River Union High School often compared to?
Mill River Union High Schoolis often viewed alongside schools like Otter Valley Union High School by visitors of our site.
What percent of students have achieved state testing proficiency in math and reading?
20-24% of students have achieved math proficiency (compared to the 40% VT state average), while 40-44% of students have achieved reading proficiency (compared to the 44% VT state average).
What is the graduation rate of Mill River Union High School?
The graduation rate of Mill River Union High School is 75-79%, which is lower than the Vermont state average of 83%.
How many students attend Mill River Union High School?
368 students attend Mill River Union High School.
What is the racial composition of the student body?
96% of Mill River Union High School students are White, 2% of students are Two or more races, 1% of students are Hispanic, and 1% of students are Black.
What is the student-teacher ratio of Mill River Union High School?
Mill River Union High School has a student ration of 9:1, which is lower than the Vermont state average of 11:1.
What grades does Mill River Union High School offer ?
Mill River Union High School offers enrollment in grades 7-12 (Supplemental Virtual).
What school district is Mill River Union High School part of?
Mill River Union High School is part of Mill River Unified Union School District #52.
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