About

Big Sky Therapeutic Services, PLLC, is an independent mental and behavioral health treatment center that was formed in 2006 by Brett Gilleo, LCPC, LMFT, and BCBA, located in Great Falls, MT. Since then, we have grown to include 15 staff members. We hold a combined total of more than 70 years experience to serve all clients’ needs and ensure high-quality results.

Originally, our services included only outpatient mental health services. Since starting Big Sky Therapeutic Services, we expanded services to include in-home parenting, in-home early intervention services, ABA (Applied Behavioral Analysis), behavioral health services, consultation, and other related services.

Our current goal is to grow as a company by increasing services for individuals with autism, related disorders, and other behavioral health disorders to help families and agencies meet the needs of our population. For more information about our services, click on the “Services” tab and click on a service type.


Our staff

Brett E. Gilleo, LCPC, LMFT, BCBA

LCPC: Licensed Clinical Professional Counselor
LMFT: Licensed Marriage and Family Therapist
BCBA: Board Certified Behavior Analyst

I have been working in the mental health field for many years. I earned my bachelor’s degree in counseling psychology from the University of Great Falls (now the University of Providence) in 1997, followed by a Master of Science in counseling in 2000. I became a Licensed Clinical Professional Counselor (LCPC) in 2001. Prior to working with Big Sky Therapeutic Services, I worked with Full Circle Counseling Solutions, AWARE, and the Center for Mental Health.

In 2012, I completed a second master’s degree in special education from Montana State University–Billings and became a Board-Certified Behavior Analyst (BCBA) in 2014. This training expanded my work with individuals on the autism spectrum and those experiencing severe disruptive behavioral health disorders.

In 2006, I founded Big Sky Therapeutic Services, PLLC, which I continue to own and operate today.

I consult with schools, daycares, Head Start programs, agencies, and families across Montana, helping assess needs and design intensive behavioral health intervention plans for youth facing a variety of challenges. I have also dedicated time to community service, including serving on the boards for Very Special Arts (VSA) Montana (2007–2016), the Great Falls Early Childhood Coalition-GFECC (2011–2020), Friends of Autism Great Falls (2015–present), and Sensibility: Autism School (2017–2019), and volunteering with the Boy Scouts of America.

Much of my work focuses on providing training, support, and mental health counseling for individuals on the autism spectrum, along with helping families advocate for appropriate special education services for their children. Although the field can be demanding, I truly love my work and find great fulfillment in helping others thrive.


Nicole, BCBA: Board Certified Behavior Analyst

Nicole

BCBA: Board Certified Behavior Analyst

I began working in Applied Behavior Analysis (ABA) as a Registered Behavior Technician in 2019 and became a Board-Certified Behavior Analyst (BCBA) in 2020.

Before entering the ABA field, I worked as a special education teacher in both residential treatment facilities and public schools. I discovered ABA while searching for effective ways to support students who were unable to access their education due to challenging or dangerous behaviors. Helping children build the foundational skills they need to learn and fully participate in their education has remained one of the most rewarding parts of my work.

I have experience supporting individuals of all ages across a variety of settings, including homes, clinics, residential placements, and school-based environments. I hold a bachelor’s degree in elementary education and special education from Montana State University, and I completed my master’s degree in educational psychology at the University of Southern Maine in 2020.

Outside of work, I enjoy reading, playing games, and going on walks and bike rides with my husband, our son, and our dog.


Tess, BCBA: Board Certified Behavior Analyst

Tess

BCBA: Board Certified Behavior Analyst

I am originally from Hungry Horse, Montana. I completed my undergraduate degree at Montana State University in 2010 and earned my master’s degree in applied behavior analysis from The Chicago School of Professional Psychology in 2013.

I am passionate about creating meaningful change for families—helping them feel confident accessing their community without fear of how their child may respond to new or challenging situations. I am equally dedicated to supporting parents and caregivers by providing tools and strategies to help them navigate difficult moments with their children.

I provided ABA therapy to families in Seattle, Washington, for eight years and in Livingston, Montana, for two years before moving to Great Falls and joining Big Sky Therapeutic Services.

In my free time, I can usually be found playing with my two boys. I love going for walks with them and my husband, and I enjoy crafting—especially crocheting or knitting items for my family. I also love reading, listening to audiobooks, and both playing and listening to music.


Alicia, RBT: Registered Behavioral Technician

Alicia

Lead RBT: Registered Behavior Technician

I was born in Great Falls, Montana, and grew up in several places throughout my childhood because my family was military. I eventually returned to Great Falls during high school, and it has felt like home ever since. My professional background includes two years of supporting adults with intellectual disabilities, and I now have the privilege of working with children diagnosed with autism.

I began my journey as a Registered Behavior Technician (RBT) in January 2024. My passion for this field comes from personal experience—a close family member of mine is on the autism spectrum and greatly benefited from services like the ones we offer. Seeing how much these programs helped him grow inspired me to be part of that same support system for other children and their families. Helping kids progress, gain confidence, and celebrate their achievements is incredibly meaningful to me.

I chose BSTS because its mission and values truly align with my own. I’m grateful to work for a company that cares deeply about the children we serve and the staff who support them. Making a positive difference in the lives of the kids I work with is what motivates me every day.

Outside of work, I love spending time with my family and dogs, getting outdoors to hike, reading good books, and painting whenever I can.


Ben, RBT: Registered Behavior Technician

Ben

RBT: Registered Behavior Technician

I grew up in Virginia and earned a bachelor’s degree in psychology from Hampden–Sydney College in 2019. From 2019 to 2024, I taught Taekwondo in my hometown, an experience that strengthened my passion for mentorship, personal growth, and community engagement. After moving to Montana in the summer of 2024, I began my career in the behavioral health field, and I joined Big Sky Therapy that August. I am deeply passionate about helping others and find great fulfillment in supporting individuals as they grow and develop.

In my free time, I enjoy exploring the outdoors, playing video games, and spending time with friends and family.


Kye, RBT: Registered Behavior Technician

Kye

RBT: Registered Behavior Technician

I was born and raised in Great Falls. Before joining Big Sky Therapeutic Services, I gained experience working with children ages 5 to 11 by helping with homework, engaging in play, and creating lesson plans. I have also enjoyed working with dogs, providing care and meeting all their basic needs.

I began working at Big Sky Therapeutic Services as a Registered Behavior Technician in 2024. I have a strong passion for helping people; I truly enjoy watching children grow, develop new skills, and celebrate their achievements. I believe learning is a shared experience—I often learn as much from the children as they learn from me, which I find incredibly rewarding.

Outside of work, I collect vintage items, solve puzzles, play video and board games, and even enjoy a good game of bingo. I also love spending time with my family and friends and building new connections.


Riley, RBT: Registered Behavior Technician

Riley

RBT: Registered Behavioral Technician

I’ve worked with children in a variety of settings for many years, and I’ve always known that I want to dedicate my life and career to supporting children with special needs. Since 2018, I’ve had the privilege of volunteering with the Camp Francis Children’s Bereavement Program through Peace Hospice—an experience that has truly shaped my passion for this work. I have also worked with the Youth Programs at Malmstrom Air Force Base and continue to volunteer with Malmstrom’s Exceptional Family Member Program.

I earned my bachelor’s degree in psychology with a minor in human development from Washington State University in 2024. Born and raised in Great Falls, I’m grateful to be back in my hometown, serving the community that helped raise me. I joined the Big Sky Therapeutic Services team in 2025 to continue pursuing my passion for helping children learn, grow, and feel supported.

Outside of work, you can usually find me with my cat and bunny, crocheting while watching a good movie, or camping, hiking, or kayaking with my family.


Gavyn, RBT: Registered Behavior Technician

Gavyn

RBT: Registered Behavior Technician

I was born in Las Vegas, Nevada, and raised in Great Falls, Montana, and both places have played a big role in shaping who I am today. I earned my undergraduate degree from Montana State University in May 2025, and I’m currently pursuing my education through Arizona State University’s online graduate program to become a Board Certified Behavior Analyst (BCBA).

My journey in behavioral therapy began in March 2024, when I started working as a Registered Behavior Technician (RBT) in Bozeman. In August 2025, I returned home to Great Falls and joined the team at Big Sky Therapy. Since then, I’ve continued to grow personally and professionally, and I feel grateful every day to be part of a field that is so meaningful. I find so much joy in teaching through play, building connection, and creating engaging, supportive experiences for the children and families I work with.

Outside of work, I’m an avid outdoorsman who loves fishing, hunting, and camping. I also thrive in social settings and truly value the relationships I build—whether I'm sharing stories around a campfire or connecting with others in the therapy room.


Juligrace, RBT: Registered Behavior Technician

Juligrace

RBT: Registered Behavior Technician

I was born in Newton, Massachusetts, but after my family moved to Great Falls when I was three, Montana quickly became home. I earned both my Associate of Science degree and my Bachelor of Science in correctional program support services, and I’ve always known that I wanted to work in a field where I could make a meaningful difference.

In April 2025, I became a CASA (Court Appointed Special Advocates) volunteer, where I advocate for children navigating the court system—an experience that has strengthened my passion for supporting kids and families. I officially became a Registered Behavior Technician in 2026, and I’m grateful to be building a career that gives me a strong sense of purpose.

I chose to work at Big Sky Therapeutic Services because of the incredible things Alicia has shared about Brett’s kindness and leadership, the impact this work has on children, and the genuine camaraderie among the staff. Once I joined, I immediately felt that same supportive, warm environment.

Outside of work, I love spending time with my family, doing puzzles, and playing video games. These are the things that help me relax, recharge, and stay connected to the people I care about.


Cherie,  Office Manager

Cherie

Office Manager

I joined Big Sky Therapeutic Services (BSTS) in 2019 as the Office Manager. I love supporting our staff, clients, and their families, and I work hard to ensure everyone has what they need to succeed.

I earned my bachelor’s degree in business management from Northern Arizona University and have spent many years managing businesses and working with children with special needs and their families. Both my volunteer and professional roles have given me a deep passion for serving this incredible community.

I have served on the board of Friends of Autism, the Youth Employment Task Force, and the planning committee for the MY Transition Conference, where I had the honor of delivering a keynote with my son in 2021. My experience and background help keep Big Sky Therapeutic Services running smoothly, and I delight in talking with families and celebrating their wins.

Outside of work, I enjoy spending time with my family, playing and learning with my grandchild, and traveling.


Cyndi, Administrative Assistant

Cyndi

Administrative Assistant

I joined Big Sky Therapeutic Services (BSTS) in 2025, bringing with me a background in medical insurance, authorizations, and accounting. After retiring once, I quickly realized I enjoy staying active and working part‑time—especially when I can use my skills to support a team and help families get the services they need. I’m detail‑oriented, love organizing and completing projects, and take pride in keeping things running smoothly behind the scenes.

Although I wasn’t born in Montana, I “got here as quickly as I could.” My husband and I moved to Great Falls years ago, fell in love with the community, and never plan to leave. This place feels like home.

Outside of work, I’m active in my church and enjoy teaching Sunday School to our youth. I also love spending time in my garden and with my sweet dog, Bella Joy.