Penobscot Valley High School, or PVHS is the only 9-12 school in the District. There are approximately 214 students enrolled, and approximately 20 teachers employed. 54% of students attending Penobscot Valley are Male, and 46% Female. There are 52 students in the class of 2009, 54 in the class of 2010, 48 in the class of 2011, and 52 in the class of 2012.

Despite the schools small size, there has been one notable graduate, Matthew Mulligan. Mulligan was signed to the Miami Dolphins in the spring of 2008 to a two year contract, as a Tight End. Throughout high school, Mulligan never played football, because it was never offered until the year after he graduated. Collegiately he played for the Maine Black Bears and also played basketball and soccer in high school. On September 22, 2008, Mulligan was signed to the practice squad of the Tennessee Titans.

"Spring Fling" is a big event for Penobscot Valley students. At the beginning of every spring, there is a day full of fun activities for all students, including a 3 Point Shootout, a Root Beer Chug, a Dodge Ball Tournament, and much more. The object of the day, is to score points for your class, most often the Senior Class is the winning class.

George Sereyko Memorial Gymnasium, or the Big Gym, is a standard sized gymnasium. The Big Gym is the separation point for HMS and PVHS. The Big Gym is technically a part of the high school, but when unoccupied, students from HMS will use it. In the winter 2007-2008, water began to leak underneath the gym floor. This caused large bubbles to form under the wood, destroying the floor. The 50 year old floor was replaced by a new, shock absorbant one.

PVHS students have an opportunity to play many different sports consisting of: Basketball, Baseball, Volleyball, Cheerleading, Soccer, Softball, Football and Wrestling. Varsity Basketball is a big sport for the small town school, where often parents, grandparents, friends, teachers, and towns people come out to cheer on their home team the "Howlers". There is also a local football team that plays at "Libby Field" right across from Penobscot Valley High School. This football team is in a private league, a league located in Aroostook County.

In the summer of 2007, PVHS underwent a massive renovation, before this, the school had many problems. The school had a very limited heating system, leaving students forced to wear jackets into class. Roofs would leak in the cramped classrooms. The renovation gave the school a complete makeover. The schools walls and roofs were redone, leaving a state approved infrastructure. Old tiles in the hallways were replaced with newer ones. The renovation left the school more atheistically pleasing. The old Workshop room, abandoned, was transformed into a new music building. Before the renovation, students had to walk outside into a run down building to go to their music classes. Under the hood changes included an advanced heating system, with a digital thermostat in every room. The school has plans to put solar panels on the roof to help with the electricity bill.

"The Portables", are a series of portable classrooms connected by a covered boardwalk. The Spanish, French, IT Department, Special Services, NWEA lab /Summer School, and the Central Office are located in this area. Penobscot Valley is the only school known to have a "Boardwalk" that goes entirely along the portable class rooms.