Faculty and Staff

Meet the dedicated team that guides our students in faith, academics, and character.

Administration

Father John Mosier

Pastor

Ordained June 6, 2019. Father Mosier attended Marquette University and served in the Marine Corps before entering seminary at Mount Angel. He also earned a degree from Saint Anselmo in Rome. He was ordained in Boise by Bishop Peter Christensen.

[email protected]

Father Celestine Agwu

Parochial Vicar

Ordained July 22, 2000. Father Celestine joined St. Mark's in August 2025 as Parochial Vicar. Originally from Nigeria, he served in Cameroon (4 years) and Canada (17 years) before joining the Diocese of Boise.

[email protected]

Mrs. Donna Gordon

Principal

Education: BA Business, BA Education, MS Educational Leadership

Mrs. Gordon began her formal educational journey at St. Paul's Catholic School in 2006. She has served as principal of St. Mark's since 2016, bringing both her business background and passion for Catholic education to the role.

Mrs. Erin Martin

Vice Principal

Education: M.Ed. — Educational Leadership

Experience: 19 years of teaching. Humor, strong relationships, and high expectations are essential to helping students grow academically and personally.

Mrs. Marie Anderson

Administration

Mrs. Rena Van Paepeghem

Administration

Mrs. Bobbi Rivas

Administration

Faculty and Staff

Mrs. Anita Martin

Preschool

Education: BA in Christian Counseling, Elementary Education Certification

Teaching at St. Mark's since 2018. Previously taught at a Catholic school in Wyoming for 6 years. "Teaching is both a profession and a ministry."

Mrs. Jacinda Johnson

Preschool

Mrs. Susan Jensen

Kindergarten

Education: BA — Boise State University, Adult Catechist Certificate — Gonzaga University

34 years of teaching and currently in her 28th year of kindergarten at St. Mark's. Inspired by Mother Teresa: "We cannot do great things, only small things with great love."

Mrs. Tiffany Lee

Kindergarten

Mrs. Brittany Brady

1st Grade

Education: BA Elementary Education with Emphasis in Spanish — University of Montana, Masters in Educational Leadership — Boise State University

Graduate of Sacred Heart and Bishop Kelly. "God gives everyone special talents and calls us to bear fruit with them."

Miss Julia Smith

1st Grade

Education: BA in Elementary Education — University of Idaho, Certified Literacy K-12

Currently pursuing a Masters in Curriculum and Instruction. Committed to fostering an inclusive learning environment where every student feels safe and heard.

Mrs. Elise Slattery

2nd Grade

Education: BA NYU in Literature with Creative Writing, MA Adelphi University in Elementary Education

Teaching Catholic education since 2006. "We create the climate — all children want to be seen and loved beyond what they can do at school."

Mrs. Melissa Pilch

2nd Grade

Education: BA Liberal Arts, Teaching Credential

Six years of teaching elementary education. Strives to create a nurturing yet structured environment where all students can learn the tools they need to be successful.

Mrs. Deanna Westmark

3rd Grade

Education: BA in Elementary Education, MEd with emphasis in ELL

Experience in grades 1st, 3rd, and 5th. Superpower: turning confusing moments into "Aha! moments" and making learning hands-on.

Miss Sarah Murray

3rd Grade

Education: BA in Elementary Education with Literacy Endorsement — Boise State University

11th year of teaching. Believes students are most successful when they feel supported, respected, and cared for.

Miss Mallory Eaton

4th Grade

Education: BA from Sam Houston State University, pursuing Masters in Education — University of Portland

From Texas, came to St. Mark's through the PACE (Pacific Alliance of Catholic Education) program. "Life with Christ is an adventure."

Mrs. Merrideth Dressler

4th Grade

Education: BA in Education, MA in Educational Management and Leadership

30 years dedicated to education. Favorite subjects: Reading and History. 9th year in the Diocese of Boise.

Mrs. Cheri Workman

5th Grade

Education: BA in Environmental Studies, MSed in Curriculum and Instruction

20+ years of teaching. Loves technology and teaching students 21st-century skills. "An investment in knowledge pays the best interest."

Mrs. Hillary Maltby

5th Grade

Education: BA in Psychology, MA in Education, Multiple Subject Teaching Credential

Has taught 3rd, 4th, and 5th grade. Teaching has always felt like her "career soulmate." She never feels like she's "going to work."

Miss Celeste Hatfield

Math & Art

Education: BA Math — Gonzaga University, Masters in Teaching — Santa Clara University

Seven years teaching in Catholic schools. "Hard work beats talent if talent never works hard."

Miss Ashley Huss

Middle School Theology & ELA

Education: BA in Theology — Holy Apostles College and Seminary

5 years teaching middle school, 6 years as youth minister, plus missionary work. "My job is to plant seeds; God's job is to make them grow."

Mr. Maximillian Groninger

Middle School

Education: BA in Business Administration

30 years of teaching in Catholic education. Has a heart to teach middle school students and a passion for forming student minds and souls.

Mrs. Nicole Schuette

Middle School ELA

Education: 6-12 English Teaching

23 years of teaching, the past 19 years at St. Mark's. Loves reading, sharing books with kids, and teaching writing.

Mrs. Wendy Behrend

Middle School Religion & Science

Education: BS in Physics, BS in Education

30 years teaching in Catholic schools. Loves incorporating dramatic arts in the classroom. Became a teacher to pass on the Catholic faith to the next generation.

Señora Rosa Mari Arrubarrena

Spanish

Education: BA from the University of Idaho — Spanish major, Business minor, ESL teaching certificate — USC

Teaching Elementary Spanish at St. Mark's since August 2016. Previously taught at Bishop Kelly and St. Joseph's Elementary.

Mrs. Kathryn Arentz

Pre-K Assistant & Art

Education: BFA in Fine Arts — Otis College of Art and Design

Over ten years teaching drawing, painting, sculpture, and graphic design to students of all ages. "If you're able to share your talents with others, it's not work. It's your calling."

Mrs. Katrina Hauck

Religion

Education: BA in Psychology — Whitworth University, Graduate Certificate in Family Engagement in Education — Harvard University, Catechist Certification

Strives to create a calm and positive environment. "I want to teach children about the unending and unconditional love that Christ has for them."

Mr. Paul Holm

Math Aide

Education: BA Mathematics — University of Nebraska, BA Accounting — Boise State University

Former actuary and tax accountant. "Mistakes are great if you learn from them." Enjoys working one-on-one with students.

Mrs. Mary Larrinaga

Preschool

Education: BA in Communications

"Every child is worthy of my attention, love and patience." Passionate about early childhood development and seeing the wonder of little minds.

Mrs. Julie Whitescarver

Instructional Aide

Education: BA in Sociology — Seattle Pacific University

Her heart is to uplift and support students and aide teachers in their daily work. "My prayer each day is that I can offer a joyful, supportive, and hardworking spirit."

Mr. Allen Rossi

Facilities

An integral part of the St. Mark's community since 2016. Always making sure the facilities are in top shape — and a fan favorite amongst the students.

Specialists

Dr. Joe Lipetzky

School Psychologist

Education: BS in Social Research, MA Scripture, MA Clinical Psychology, Psy.D. Clinical Psychology

37 years as a therapist, teacher, and presenter. Methods include Thomistic Psychology, Attachment Therapy, Cognitive Therapy, and Behavior Therapy.

Mrs. Sarah Lynch

School Counselor

Education: M.Ed. School Counseling, B.S. Elementary Education K-8

11 years teaching in Catholic schools, 4 years as school counselor at St. Mark's. "Every child deserves to feel understood, supported, and capable of growth."

Mrs. Melissa Brady

Reading Specialist

Education: BSED Elementary Education — University of Missouri, MA Literacy — Boise State University

19 years of teaching, 10 at St. Mark's. "I became a reading teacher because my own child struggled with reading and I wanted to find ways to help all children learn."

Nurse Sherry Placido

School Nurse

Education: Early Childhood Development, Certified Nursing Assistant, Heart Saver CPR Instructor

Nearly 20 years with Saint Alphonsus. Over half those years in the School Health Program as well as direct patient care in the hospital.