The Timberline Difference

Timberline Builders has refined the process of custom home building from design to construction. The Timberline Difference has everything to do with people. We build with excellence, but more importantly, we care about personal growth in ourselves, our employees, and in the lives of the clients we get to serve. We have a rich history and strive to continue to build our team to exemplify integrity, relationship, thoroughness and fairness.

Our History

Timberline started in 1973 when Ralph Greslin, a draftsman who worked for a local lumberyard, decided the office environment and his tiny cubicle were too constraining for his taste. With a small pile of hand tools and a six-foot ladder, he began a venture to start his own construction company. The first job he had lined out was a small kitchen remodel, which ended up falling through shortly after giving notice that he would be leaving his draftsman position.  However, he wasn't deterred from moving forward with the dream he knew he needed to pursue. He embraced the process of growth by facing many challenges along the way and learned the value of flexibility and tenacity. Ralph and his wife, Carleen, owned and operated Timberline Builders for 39 years, laying a strong foundation of honesty, financial responsibility, and the value of people before profit.

Meet the Team

Michael & Jenny Greslin, Owners

Always eager to help his dad, Ralph’s son, Michael, spent his summers working with the crew throughout junior high and high school.  He worked as a laborer, a carpenter, and a foreman until 2008 when he became the General Manager.  Michael and his wife, Jenny, purchased Timberline Builders in December of 2012.  Currently, Michael oversees all aspects of the business. Although his primary focus is on keeping the vision out in front of the team, he still loves the hands-on aspect of construction work and it's not unusual to find him sitting in an excavator preparing a new job site.  Michael and Jenny live in Spearfish with their four boys...and it appears as though the love for building has passed down to another generation! 

Dustin Olson, Owner/Construction Superintendent

Dustin started as a laborer with Timberline Builders in 2004 and became an owner in 2020! From the onset, he has demonstrated incredible proficiency in the trade.  Over the years, he has steadily applied himself, honing his skills and becoming an excellent craftsman.  Dustin currently still serves as a Construction Superintendent and is highly skilled in managing projects with thoroughness and efficiency.  Dustin and his wife Amy have two daughters. His passion is hunting, and he enjoys spending time with family and friends while camping, fishing, and many other outdoor activities.

Greg Detweiler, Construction Superintendent

Greg was in the construction business for 17 years before joining Timberline Builders in 2014.  He brings a broad range of experience, creative ideas, strong attention to detail, and a great appreciation for beautiful views and the location of various projects.  Greg and his wife, Twila, have four grown daughters, two son-in-laws, and five beautiful granddaughters. Greg enjoys fishing and hiking in the mountains and discovering new picturesque settings and landscapes.

Our Core Values


We believe in doing what’s right and are actively focused on the development of our character.  We make a conscious choice to do what we say we will do and authentically are who we present ourselves to be.  Our goal is to lead with consistency in our actions, methods, and outcomes.


We recognize that the building process involves entering into a partnership that requires mutual trust.  We value this process and take the necessary time to build that trust with our clients through open communication, honesty, and collaboration.  We place the same value on the relationships we have with our many sub-contractors, material suppliers, and company employees.  At the end of the day, we really are in the people business.


We are attentive to accuracy and detail. We are committed to completion without negligence or omissions.  We hold ourselves to consistent standards that can be seen in the soundness of our building practices and in the way we communicate.


From the initial cost proposal to requested changes that arise during the building process, we treat our clients with respect and fairness. We know the value of our craft as well as the value of your investment and make every effort to ensure you are getting the best your money can buy.