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

Brett has been working in the mental health field for many years. He earned a bachelor’s degree in counseling psychology from the University of Great Falls, now University of Providence, in 1997, obtained a Master of Science degree in counseling in 2000, and became a Licensed Clinical Professional Counselor (LCPC) in 2001.

In 2012, he obtained a second master’s degree in special education from Montana State University in Billings and achieved status as a Board-Certified Behavior Analyst (BCBA) in 2014. The BCBA certification furthered his work in the field of autism spectrum disorders, as well as severe disruptive behavioral health disorders.

During his career, Brett has worked for Full Circle Counseling Solutions, A.W.A.R.E., Inc., and Center for Mental Health. He currently owns and operates Big Sky Therapeutic Services, PLLC, which he started in 2006.

Brett consults with schools, daycares, Head Start programs, agencies, and families across Montana to help assess and design intensive behavioral health intervention plans for youth with various challenges. Brett’s community service includes volunteering his time to serve on the board for the Very Special Arts (VSA) program in Montana (2007-2016), Great Falls Early Childhood Coalition (GFECC) from 2011-2020, Friends of Autism Great Falls (2015-present), and Sensibility: Autism School from 2017- 2019.

Brett spends much of his time providing training, support, and mental health counseling for the autism spectrum population, as well as assisting families in advocating for special education services for their children. Although the field can be challenging, he genuinely loves his work and finds helping others highly rewarding.


Lisa, BCBA: Board Certified Behavior Analyst

Lisa

BCBA: Board Certified Behavior Analyst

Lisa started working in the field of ABA in 2015, as a registered behavior technician. She is currently a Board Certified Behavior Analyst (BCBA).

Prior to her adventure into ABA, Lisa worked in the schools and taught pre-K in Japan. During her time there, she met a friend that introduced her to ABA. When Lisa returned to the states she started working at a small clinic in Indiana, before moving to Great Falls, MT, in 2021.

Lisa has experience working with individuals ages 4 to 64, providing ABA services and behavior management through the waiver system. She has worked in clinic settings and has also provided services in the home and community settings. Lisa has a bachelor’s in Social Psychology from Park University and received her graduate degree from Ball State University in 2017.

Lisa enjoys spending time with her kids and is always ready for a road trip and adventure.


Dani, BCBA: Board Certified Behavior Analyst

Dani

BCBA: Board Certified Behavior Analyst

Dani has been working in the behavioral health field for many years. In 2013 she earned her Bachelor’s degree from the University of North Florida in Psychology & American Sign Language, and her Master’s degree in Special Education & Applied Behavioral Analysis at the University of West Florida. In college Dani volunteered doing Equine Therapy sessions for children with special needs and conducted culinary programs for children on the autism spectrum and other varying exceptionalities. After earning her degree, she worked as a Vision Therapist with children and adults to improve their visual processing skills, and then transitioned into the field of Applied Behavioral Analysis in 2017. Dani has worked in clinics and as a Special Education Paraprofessional providing ABA approaches to learning and behavior modification. Dani loves her work at Big Sky Therapeutic Services and has transitioned from and RBT, to BCaBA to a BCBA. Her experience enhances her work with our children and their families.

Dani loves spending time with her husband and exploring the outdoors.


Mollie, BCBA: Board Certified Behavior Analyst

Mollie

BCBA: Board Certified Behavior Analyst

Mollie received her undergraduate degree in Special Education with a Generalist Teaching License in 2014 from the University of Northern Colorado. With her degree, Mollie has taught in a variety of settings and has had the privilege to work with a wide range of students varying in age and disability. Mollie also has experience working both in the homes and within the schools as a Special Education Teacher and RBT. During her time as a Special Education Teacher, Mollie was introduced to the world of ABA and saw how impactful the use behavior principles were and decided to pursue getting her Masters in ABA. In 2017, Mollie graduated as an Intervention Specialist with an emphasis in Applied Behavior Analysis from the University of Northern Colorado. In 2021, Mollie passed her BCBA exam and started her journey as a BCBA. She recently moved to Montana and is excited to get to know this great state.

In her free time, Mollie enjoys being outdoors, exploring new towns, reading, hanging out with family and friends, as well as training/having lazy days with her dog.


Ashlyn, BCBA: Board Certified Behavior Analyst

Ashlyn

RBT: Registered Behavior Technician

Ashlyn has been working in the field of special education for many years. She began this career working as a Direct Support Specialist, supporting children with various special needs. She first received her Registered Behavioral Technician (RBT) certification in 2016 and gained experience working with children with autism. Her love for this population lead her to work as a Special Education Paraprofessional with the Great Falls Public School District. The school district gave her the opportunity to work with a wide variety of needs and abilities but again the population that captured her heart were the children with autism. Ashlyn’s love for these special kids brought her back to working as an RBT. In 2021 she joined Big Sky Therapeutic Services where she uses her skills and experience to help our kids learn and grow. Ashlyn hopes to go back to school and get her Master’s degree in Applied Behavior Analysis.

Outside of work, Ashlyn enjoys spending time with her family, crafts and enjoying Montana’s great outdoors and fishing.


Maddie, RBT: Registered Behavior Technician

Maddie

RBT: Registered Behavior Technician

Maddie has worked with children, of all ages from newborn to teens, for many years. She is originally from Boulder, MT and first started working with children teaching swimming lessons. She babysat throughout the summers and after school/work. She worked at Head Start in Boulder before transitioning to a Special Education Paraprofessional role at the elementary school. She moved to Great Falls in April of 2023 and started working for Big Sky Therapeutic Services as a Registered Behavioral Technician (RBT). She says, “I am in love with being an RBT and working with all our families”. Her love for these children shows in her passion and care for them. She skillfully guides them to achieve goals as they continue to grow. “There is so much to learn in this field and every day brings its own rewards. It has been incredible getting to know the kids and watching them grow through the services we provide.”

In her free time, Maddie enjoys spending time with family and friends, cross stitching, and playing video games.


Meredith, RBT: Registered Behavior Technician

Meredith

RBT: Registered Behavior Technician

Meredith began working in the behavioral health field as a Direct Service Provider, supporting children with varied developmental needs. She came to Big Sky Therapeutic Services in 2022 as a Registered Behavior Technician (RBT). She is enjoying gaining experience in the Applied Behavior Analysis (ABA) field and in supporting children with autism. Meredith graduated with highest honors from Montana State University (MSU) where she obtained her Bachelor’s degree in Psychology, with a minor in Human Development, and Economics. Her love for the field of ABA and working with children with autism brought her back to Big Sky Therapeutic Services where she applies her knowledge and continues to share her experience with our special kids. Meredith plans to continue her experience in the ABA field, and work towards getting her master’s degree.

Meredith enjoys being outside, staying active, and spending time with friends and family.


Keely, RBT: Registered Behavior Technician

Keely

RBT: Registered Behavior Technician

Keely began her career as a Special Education Paraprofessional for Great Falls Public Schools in 2019. She started as a one on one before moving to help kids in K-6th grade. Keely came to Big Sky Therapeutic Services in 2021 and received her Registered Behavioral Technician certification (RBT). She has worked with children with autism, ADHD, and various learning disabilities for many years. Keely put in many hours of volunteer work around the community to enhance the lives of special needs individuals; she has written and performed skits at the Friends of Autism Conference, taught theater workshops to self-contained classes to enhance verbal and nonverbal communication skills. Keely has enjoyed supporting Friends of Autism, Eagle Mount and the GFPS Special Ed students through theater over the years. Her past skills and experience enhance her role as an RBT where she enjoys helping our children grow and watching them mature.

Keely enjoys traveling with her husband and photography in her free time.


Azaya,  RBT: Registered Behavior Technician

Azaya

RBT: Registered Behavior Technician

Azaya has been working with individuals with developmental disabilities for many years. Her love for this population lead her to obtain her certification as a Registered Behavioral Technician (RBT). She has an Associates of Arts degree and is currently continuing her education in ABA services to eventually become a BCBA. She began working with developmentally disabled elderly adults originally from state facilities in a group home setting. Because of this, she is very passionate about clients’ rights, dignity, choice and living a fulfilling life. This is where she began learning about ABA services and the benefits of early intervention for those on the autism spectrum. She then switched to working with kids, in home and center when she was still living in Arizona. Once moving to Montana, she knew she wanted to continue this path and find a clinic with the same ideals as her. She knew that Big Sky Therapeutic Services was the place for her to continue growing and learning in the ABA environment. Here she can share her past knowledge and experience with our children and families.

When she’s not working you can find her spending time with her family and dogs, going on adventures to new places, learning new things or taking photos of all the beautiful places she goes.


Cristina, Family Intervention Specialist, SafeCare Provider

Cristina

Family Intervention Specialist, SafeCare Provider

Cristina was born and raised the youngest of seven, here in the great state of Montana. She grew up on a farm outside of Great Falls. Family means the world to her. She and her husband have 5 grown children and many many grandchildren. As a family, they have enjoyed many adventures in the beautiful outdoors, in the mountains camping, on the river fishing, or just going for a drive. Gardening is one of her favorite pastimes, as well as sewing, woodworking, and crafting.

She has experienced working in the medical field, working in a school environment, running a small woodworking business, for a time as an in-home daycare provider. All these experiences have helped equip her to work as a Family Intervention Specialist, SafeCare Provider. Family is her passion, and she shares this passion with her SafeCare families. She has been a certified SafeCare Provider since June of 2019. She enjoys getting to know new families and enjoys seeing the positive growth that can happen in their lives when they choose to seek a new direction.


Cherie,  Office Manager

Cherie

Office Manager

Cherie joined BSTS in 2019 as their Office Manager. She helps look after staff, clients, and their families to make sure everyone has what they need. Cherie graduated with a Bachelor’s degree in Business Management from Northern Arizona University and has a long career of managing businesses as well as working with special needs children and their families. Her volunteer and paid positions have given her a true passion for this special population. She sat on the board for Friends of Autism, Youth Employment Task Force as well as the planning committee for MY Transition Conference where she was a keynote speaker with her son in 2021. Her experience and knowledge help keep Big Sky Therapeutic Services running smoothly. She loves talking with families and celebrating their wins.

Outside of work Cherie enjoys spending time with her family, traveling and learning together.