Marcus Mahlen, CCIM, SIOR

Senior Vice President Download Profile

Scope of Service

Marcus Mahlen joined NAI Sioux Falls in February of 2017 as a broker associate. Since the beginning of his time at NAI Sioux Falls, negotiating his first deal at the age of 23, Marcus has shown a passion for putting his client first. His strong work ethic and ability to form strong personal connections in the community has allowed him to work on a number of significant projects for NAI Sioux Falls, including being involved in the Deal of the Year for 2018.

Marcus has completed over 200 sales and leases on behalf of his clients through 2021. These transactions have totaled over 1.5M square feet of building area and 12.5M square feet (+/- 287 acres) of development land. These transactions have totaled over $100M in sale/lease value. His expertise primarily involves investment sales and leasing in the industrial, office, and retail asset classes.


  • 2022 – SIOR Designation
  • 2019 – CCIM Designation
  • 2018 – NAI University in Baltimore, MD, MiCP designation – Masters in Commercial Property from The Lipsey Company.
  • 2015 – University of South Dakota – Bachelor of Business Administration with an emphasis in Business Marketing, minor in Political Science.

Professional Affiliations & Designations

Community Involvement

  • Harrisburg Economic Development Corporation Board Member (December 2019 – Present)
  • Southeastern Development Foundation Board Member (. 2021 – present)
  • Sioux Falls Area Young Professional Network Steering Committee Board Member (October 2017 – Present)
  • YPN Civic Engagement Committee Co-Chair (May 2018 – Present)
  • Sigma Alpha Epsilon Sioux Falls Area Alumni Association President (June 2017 – Present)
  • Sioux Falls Area Chamber of Commerce Issues Management Council Member (June 2018 – Present)
  • Leadership South Dakota Class of 2019 Graduate
  • University of South Dakota 30 Under 30 Honoree (2018)
  • 2018 Sioux Falls School Board Facilities Task Force Member
  • Sioux Empire United Way Emerging Leader Board Member (May 2018 – May 2020)
  • 2018 Sioux Council Friends of Scouting Co-Chair
  • Active Yelduz Shriner
  • Sioux Council Executive Board Member (November 2019 – November 2020)

What People Are Saying about Marcus Mahlen, CCIM, SIOR

“I had reached out to Marcus in early spring of 2020 about a possible office move. Once COVID struck, all plans were put on hold. I decided to put the move on hold for a year and told him to check back with me. As promised, he reached out early spring 2021 and I knew it was time to start the search. We found the perfect space and with his extreme knowledge and expertise was able to work with me and propose an offer that I produced and wanted, with no pressure by him. I couldn’t have asked for a better outcome. Marcus is my recommendation for a “go to” Agent if you want the BEST!”

Robin Sorlie

Spectrum Home Care & A Spectrum of Care

“2020 was a challenging year for most businesses, but office leasing must have been at the top of that list! Marcus Mahlen was incredibly persistent in listing, showing and obtaining a signed lease for my office space despite the added challenges of a pandemic and work-from-home focus. I would recommend NAI Sioux Falls for all of your commercial real estate needs; they exceeded my expectations in every way.”

Korena Keys

KeyMedia Solutions

Reed Burson
Short Staffed, Inc.

Stacey Tieszen
CASA Sioux Falls

Emily Learing
Encompass Mental Health, LLC

Archit Shah
OrangeTheory Fitness Sioux Falls

“Marcus did a great job coming up with various options to try to fit our needs and once we zeroed in on an option, he was great at negotiating with the lessor and us for terms that worked for both parties.”

Patrick Sweetman

“Marcus is a true team player that puts client needs over his own! I had a tight timeline to find an office and not much knowledge of downtown office space and what I actually wanted or needed. However, Marcus made himself available immediately and he quickly understood my needs, making them his focus. Even though the properties he was currently responsible for didn’t meet my needs, Marcus made sure that NAI did by unselfishly connecting me with another team member who represented a more appropriate space. His market knowledge, willingness to collaborate, and focus on understanding/meeting client needs with urgency really simplified the process for me. I would highly recommend Marcus!”

Brandon Eastman

Top Talent Connection, LLC

“Marcus was informative and kept us in the loop throughout the whole process, which made the transaction that much easier. We couldn’t have asked for a better agent!”

Mandy Rounseville

Sioux Falls Audiology Associates

“Thank you, Marcus, for your efforts on the sale of our property in Ipswich SD. NAI of Sioux Falls, and yourself, were a great team to help us with this sale. Everything was very professional, and the communication was superb. It is so nice to get answers when needed, and in a timely manner. We will certainly use you in our next need for selling one of our properties. I will not hesitate to refer you to anyone looking for help as well!”

Dirk Swanson

Double L Investments – Aberdeen, SD

“Our Church made a difficult decision to not build a new building but rather look for an existing building or space to remodel instead.  Finding an existing building or space to fit a church can be extremely difficult.  Marcus took the time to listen to the specific needs and wants of the church before attempting to locate properties.  That approached help narrow the search for him and helped us keep an open mind on the options presented.  In the end we found the right fit and Marcus made it happen.  We are very appreciative of Marcus’ thorough approach and professionalism.” 

Galen Van Otterloo

Arise Church


“I had been searching for the right office for my small business for several months and had worked with a few different property management companies without any success. That was until I worked with Marcus [Mahlen]. Marcus took an entirely different approach from other commercial real estate brokers and took the time to precisely understand what our needs were and provided an office solution that exceeded my expectations. What is more, Marcus made the entire process of leasing an office space straight forward and effortless. I could not recommend Marcus and NAI highly enough.” 

Nathan Fredrickson

EPI – Director of Investigations & Risk Management

“As a church we have very specific needs, strict budgets, and lots of red tape to get through when it comes to real estate transactions. Marcus and NAI were phenomenal every step of the way – they were patient, easy to work with, and got things done promptly. We couldn’t have had a better experience.”

Jeff Mueller, Pastor

Restore Church – Yankton

“When it comes to real estate deals, my office was small potatoes. Even though the deal was not big, and the negotiations were a little tense, Marcus was cooler than a trillion ton iceberg and got the deal everyone was happy with.”

Josh Tordsen

Gigastrand Technologies

“We needed a specific type of warehouse space, Marcus continued searching until he found one that worked for our needs. He is a true professional.”  

Keith Auch

Reclamation Technologies, Inc

Office Number: (605) 357-7100

Mobile Number: (605) 228-9744

Fax Number: (605) 357-7102

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