Mission Statement
The mission of St. Mark’s Evangelical Lutheran School is to assist the parents in the spiritual and academic training of their children by proclaiming the Gospel of Jesus Christ on the basis of Holy Scripture and teaching the academic curriculum from a scriptural viewpoint.
All of this we do to the glory of God out of thankfulness and praise as the Holy Spirit works to nurture the children as they prepare for this life and for eternity.
Our school is all about Jesus Christ!
History & Beliefs
For more than 150 years, St. Mark's has focused on assisting the parents of our congregation in the spiritual and academic training of their children.
Our faculty and staff recognize that each child is a unique gift given by God, and that our children learn best when parents and teachers work together for the benefit of each child.
We believe that education is rooted in the knowledge and wisdom of Jesus Christ. For that reason, our curriculum is designed so that our students are growing daily in a life of faith, witness and service.
Our purpose is to serve families of our congregation who desire not only a private education, but a Christ-centered education for their children. All subjects at St. Mark's are taught from the perspective of the Word of God revealed in the Bible, and understood by the Wisconsin Evangelical Lutheran Synod (WELS).
School Faculty
Kelsey Hensler
Child Care Director
Kelsey Hensler
Child Care Director
Kelsey Hensler is the director of St. Mark’s Lutheran Childcare Center, which is a year round childcare center for children 2.5 years to 10 year olds. She has been the director since June 2022.
Miss Hensler has many years of experience working with children. She has worked in several childcare centers and schools, where she has been a childcare teacher and director. St. Mark’s is her home church where she grew up and attended grade school. Her father and grandmother also attended school at St. Mark’s, as well. She has lived in Watertown her whole life. Miss Hensler attended the University of Wisconsin - Green Bay (2008), where she got her bachelor’s in Psychology and Human Development.
Carol Tetzlaff
Pre K-3 and K-4
Carol Tetzlaff
Pre K-4
Mrs. Tetzlaff is the Preschool Director and the PreK-4 teacher.
Mrs. Tetzlaff grew up on a dairy farm north of Juneau, WI. She attended grade school at St. John's Lutheran School in Juneau and high school at Martin Luther Prep School (MLPS) in Prairie du chien, WI. She graduated from Dr. Martin Luther College (presently Martin Luther College) in 1988.
She has taught in Nebraska, Michigan, and now Wisconsin.
She is married to Pastor Tetzlaff who serves 2 churches in Ixonia (St. John's, Ixonia and St. Mark's, Sugar Island). Pastor and Mrs. Tetzlaff have 3 children.
Sue Hahn
Kindergarten
Sue Hahn
Kindergarten
Mrs. Sue Hahn is our full-day Kindergarten teacher.
Mrs. Hahn, a fourth generation teacher, assists with the library and serves on the Booster Club. She is a native of South Milwaukee, Wisconsin and attended Zion Ev. Lutheran Grade School. Mrs. Hahn is a 1973 graduate of Wisconsin Lutheran High School in Milwaukee, Wisconsin. In 1977 she earned her Bachelor of Science Degree in Education from Dr. Martin Luther College (presently Martin Luther College) in New Ulm, MN.
Summary of Mrs. Hahn's teaching ministry:
- 1977-1978 | Grades 4-5 at St. John's-North Trinity, Milwaukee, WI
- 1978-1981 | Grade 3 at St. Mark's, Watertown
- 1994-2006 | Pre-Kindergarten at St. Mark's, Watertown
- 2006-Current | Kindergarten at St. Mark's, Watertown
Mrs. Hahn and her husband, Ed, live in Watertown and have 2 sons, a daughter and son-in-law, and one grandson. Her hobbies include spending time with family, scrapbooking, card making, walking and reading.
Natezia Fredrick
1st Grade
Natezia Fredrick
1st Grade
Meet our new 1st grade teacher!
Tammie Kassulke
2nd Grade
Tammie Kassulke
2nd Grade
Mrs. Kassulke is teaching a second grade classroom this year and directing Alpha choir.
Mrs. Kassulke grew up in Lake Mills, WI, attending St. Paul's and Lakeside Lutheran High School. She then attended Dr. Martin Luther College. After graduating from college she taught at St. Paul's, Cudahy, WI, before marrying and moving to Norfolk, NE, where her husband was teaching. During the twenty-plus years they lived there, she cared for their five children, did substitute teaching, band lessons, assisted with choirs and eventually taught a combination first and second grade room. Mrs. Kassulke has also taught first grade at Mt. Calvary, in Waukesha, WI, and Trinity-St. Luke's in Watertown.
Perhaps her lifelong love of books explains why she so loves teaching first graders and showing them the joy of reading. What a privilege to share this love and that of our Savior with His little lambs!
Niki Skaer
3rd Grade
Niki Skaer
3rd Grade
Mrs. Skaer graduated from UW-Whitewater with her degree in Elementary Education and a minor in History. She worked at a Lutheran school in Milwaukee for two years and as a long term substitute for a year in the Hartland area. She started at Lebanon Lutheran School in 2018 as the 3/4 teacher and loves being part of this amazing community. She is nearing the end of her synod certification courses to be WELS certified.
She and her husband, Bret, moved to Watertown in 2018 and are blessed to have two daughters, Ally and Maggie. They are expecting their third baby this November. In her free time, she enjoys spending time with her family, playing with her daughters and teaching them new things, working on crafts and photography and being in the sun.
David Hirsch
4th Grade
David Hirsch
4th Grade
Mr. David Hirsch serves as our fourth grade teacher, teaches physical education for grades 3–5, and is taking on the role of Athletic Director. He attended Luther Preparatory School in Watertown, Wisconsin, and then went on to graduate from Martin Luther College in New Ulm, Minnesota. He double majored in Elementary Education and Secondary Social Studies.
Before joining our faculty, Mr. Hirsch taught 11th grade at Luther Prep from 2023 to 2025, where he also served as tutor (dormitory supervisor). He is excited to now work with younger students and to encourage their growth, both in the classroom and through athletics.
In 2021, he married Claire Pagels. Mr. Hirsch enjoys sharing the love of Christ with his students and helping them grow in faith and character, as well as catching a game over the weekend.
Brenda Koester
5th Grade
Brenda Koester
5th Grade
Mrs. Brenda Koester serves as our fifth grade teacher. She attended grade school at St. Pauls in Fort Atkinson. After graduating from Lakeside Lutheran High School. She attended DMLC in New Ulm, MN,
She has taught children from age three up to 8th grade. She has been blessed to have served as school Music coordinator, coach of various teams and as organist. She has served the Lord in Michigan, Wisconsin, and Minnesota.
She married Jason Koester after meeting him at high school. They have been blessed with four children and four grandchildren. Mrs. Koester enjoys sharing the Love of Christ with God’s precious little ones. In her spare time, she loves to read, bake and cheer on her family.
Kristen Behl
6th Grade
Kristen Behl
6th Grade
Mrs. Behl earned a bachelor's degree in Exercise Science (2013) and a doctorate degree in Physical Therapy (2015) from Carroll University in Waukesha. She worked as a physical therapist for ten years, and continues to cover clinic hours occasionally for Watertown Regional Medical Center. She began teaching in various roles at St. Mark's in 2022, and officially entered the public ministry in 2025. She is working toward earning her Synod certification through MLC.
Mrs. Behl married her husband Phil in 2013. They were both graduates of the Lakeside Lutheran High School class of 2009. They joined St. Mark's congregation in 2015, and now have two daughters, Eva and Olivia. They enjoy traveling as much as they can, with a particular love for Alaska.
Mrs. Behl enjoys outdoor activities like hiking, water skiing, paddle boarding, Jeeping, salmon fishing and camping. She also finds immense joy in children's books, and has written and published a few of her own. She is excited to foster a culture of reading in her classroom each year, as she believes reading opens doors for lifelong learning and a love of dwelling in God's Word.
Tim Kassulke
7th Grade and Assistant Principal
Tim Kassulke
7th Grade
Mr. Tim Kassulke serves St. Mark's Lutheran School as assistant principal. Mr. Kassulke also serves as educator in the 7th grade homeroom as well as leading the 7th grade in Bible study twice a week, math, and literature. Additionally, Mr. Kassulke serves as the Social Studies teacher for grades 6-8 and teaches grades 6-8 music.
Mr. Kassulke was born and raised in Milwaukee, Wisconsin. He attended Lutheran Elementary School at Christ of Milwaukee. Mr. Kassulke graduated from Wisconsin Lutheran High School in 1981. Dr. Martin Luther College (currently Martin Luther College) trained Mr. Kassulke to be a Lutheran educator graduating in 1985.
Following graduation Mr. Kassulke served St. Paul of Norfolk, Nebraska for 23 years and Mount Calvary of Waukesha, Wisconsin for 6 years. Mr. Kassulke began his service at St. Mark's in 2014.
Mr. Kassulke earned a Master’s Degree in Curriculum and Instruction from Doane College of Crete, Nebraska. A professional growth highlight was attending a weeklong Teachers’ Institute at Colonial Williamsburg. Mr. Kassulke became a National Geographic Certified Educator in March of 2020.
Mr. Kassulke married Tammie Yanggen in 1986. Mr. and Mrs. Kassulke have been blessed by God with 5 children; a son married and living in Independence, Missouri, a son married and living in Waco, Nebraska, a daughter married and living in Milwaukee, a son residing in Dallas, Texas, and a daughter living in Waukesha. Mr. and Mrs. Kassulke are blessed by God as well to be grandparents to six grandchildren.
Therefore, my dear brothers, be steadfast, immovable, always abounding in the Lord’s work, because you know that your labor is not in vain in the Lord. (1 Corinthians 15:58), is a favorite Bible passage encouraging Mr. Kassulke as he serves in the Lord’s kingdom.
Casey De Frain
8th Grade
Casey De Frain
8th Grade
Mr. De Frain serves as our 8th Grade teacher and upper grade Science. Mr. De Frain is our school technology coordinator.
Mr. Casey De Frain is a native of Cudahy, Wisconsin. He spent most of his life in Phoenix, Arizona. He is a 2004 graduate of Arizona Lutheran Academy in Phoenix.
In May 2008, he graduated from Martin Luther College in New Ulm, Minnesota with a Bachelor of Science in Education and an emphasis on Science. He has been serving at St. Mark’s since July 2008. He received his Master’s degree in Educational Technology from Martin Luther College in May 2017.
In 2010, he married his best friend Jaymie De Frain (nee Bergmeier). They have three children: Martha, Esther, and Asa. They bring him much joy in his life!
You may get more information about his classroom here.
Fred Uttech
School Administrator
Fred Uttech
School Administrator
Mr. Frederick Uttech serves as the School Administrator for St. Mark’s Lutheran School. Mr. Uttech is responsible for the educational program of the school, the pre-school program, and the extended care program. He also oversees the lunch program and maintenance program of the school. Mr. Uttech teaches one of the upper grade math classes.
Mr. Frederick Uttech is a native of Watertown, Wisconsin He attended St. John’s Lutheran Grade School. He is a high school graduate from Northwestern Prep School (presently Luther Prep School) in Watertown. He graduated from Dr. Martin Luther College (presently Martin Luther College) in the spring of 1972. He served as an instructor at Northwestern Prep and College from 1972-1974.
The other congregations where he served were Bloomington Ev. Lutheran Church and School located in Bloomington, Minnesota from 1974-18980 and Bethany Ev. Lutheran Church and School from 1980-2007 located Manitowoc, Wisconsin.
Mr. Uttech holds a Wisconsin State Professional Educator’s License. He is a Certified Reading Teacher holding a 316 Wisconsin State Reading Teacher License. He completed his Master’s Degree through Silver Lake College in Manitowoc in the area of Educational Leadership. Mr. Fred Uttech has served at St. Mark’s since the mid-summer 2007.
Mr. Uttech serves as the WELS Western WI District Schools Coordinator serving 45 Lutheran Elementary Schools in the Western part of Wisconsin. As part of that position he serves as the director of the WELS Western WI District School Counselor program.
Mr. Uttech and his wife Peggy, live in Watertown. They have four grown children all of which are married and they have fifteen grandchildren.
Mr. Uttech loves serving His Lord by serving the families of St. Mark’s and their children.
Jessica Backus
Special Education Teacher
Jessica Backus
Special Education Teacher
I was born and raised in Oconomowoc, WI, to Ralph and Tracy Schmidt and have one younger sister, Heather, who is also a WELS teacher. I spent my grade school years attending St. Matthew’s Lutheran School and then attended Luther Prep for high school. After graduating from Prep, I attended Martin Luther College where I received my elementary education degree. While attending MLC, I met the love of my life, James Backus. We got married in August of 2000, after our sophomore year. Our first baby, Abel, was born a few short months after our graduation from MLC in 2002. I have been so blessed to be a stay-at-home momma for the last 21 years adding Annemarie, Elizabeth, Mary, Micaiah, Judah, Justus, Levi & Elisha to our family along with one baby in heaven. We have lived in the states of WI, MI & SD. I feel so very blessed to begin this new journey in my and my family’s life! Spending each day in the classroom with Jesus’ precious children is a humbling privilege that I am looking forward to.
Bret Skaer
CFS-Mental Health Support
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Bret Skaer
Mental Health Support Counselor
Bret joined Christian Family Solutions in 2021 as a Mental Health Support Specialist. He earned his BS in Psychology from University of Wisconsin – Whitewater. Bret is currently working towards his Master of Clinical Mental Health Counseling at Bethany Lutheran College. Bret would like to specialize in working with children and adolescents struggling with emotional or behavioral challenges, including, but not limited to mood disorders, OCD and anxiety, and personality disorders. Bret’s previous experiences include working in a school setting in Milwaukee and more recently working in residential and inpatient care for behavioral health.
Bret is a member of St. Mark’s with his family. He married his best friend, Niki, in 2016. They moved to Watertown in 2018 and welcomed their first daughter, Ally, shortly after. They then welcomed their second daughter, Maggie, in 2020. This November the will be welcoming their third child.
Becca Palacios
Hispanic Liaison
Becca Palacios
Hispanic Liaison
News to come!