Calhoun W. Cox, Jr., Founder

Cal Cox grew up in Seneca, South Carolina and received his Bachelor of Science from Clemson University in 1964.

He served in the Army Corps of Engineers/Special Forces for seven years and is a veteran of the Vietnam War.

Cal worked in the construction industry for 36 years and founded Calcon Constructors in 1981 in Denver, Colorado.

Throughout the years, Cal served as the President of the Associated General Contractors of Colorado, as well as on numerous boards and committees. 

James P. Bosshart, Co-Founder and Chairman

Jim graduated with distinction from Iowa State University with a Bachelor of Science in Construction Engineering.

Jim co-founded Calcon Constructors in 1981 and currently serves as Chairman. He is involved in all business aspects, including marketing, estimating, project management and office management.

Jim is very involved in the industry; he has served on many committees, including a position as Executive Committee Board of Directors for the Associated General Contractors of Colorado.

Joseph S. Gallion, Jr., CEO

Joe, who received his education from Colorado State University, has been with Calcon since 1982, and currently serves as the company’s CEO.

Joe is responsible for all business aspects, including: marketing, estimating, project management and field management.

He remains very active in the construction industry, and has held positions as the Chairman of Colorado Neurological Institute, Chairman of the Board for Southwest Family YMCA and as the past President of the Construction Industry Training Council.

Presently, Joe sits on the board of AGC Colorado and is a member of the National Western Stock Show.

When not in the office, Joe enjoys golfing, skiing, cycling and traveling.

Brian Mortimore, President

Brian has been with Calcon since 1999 and is currently a President of the company. He is a proud CSU alumnus and graduated with a Bachelor’s degree in Construction Management.

With over 20 years of experience in Project Management, Brian is a vital asset to Calcon’s customers and vendors.

Brian has completed many notable projects for Calcon in the retail, technical, healthcare and mixed-use categories.

He is LEED AP certified and a Certified Healthcare Constructor.

In his free time, Brian enjoys golf, the outdoors and spending family time with his wife and twin girls.

Jim Sexton, CFO and Vice President

Jim Sexton has dedicated his career to construction-related accounting and finance since relocating to Colorado in 1999. Joining the Calcon Team in 2013, he brings extensive expertise as a Certified Public Accountant (CPA) and Certified Construction Industry Financial Professional (CCIFP). Jim earned his Bachelor of Science in Accounting from Northern Illinois University.

Currently serving as CFO, Vice President, and Stockholder, he oversees all facets of accounting, financial reporting, information technology (IT), and human resources (HR).

Outside the office, Jim finds solace in golfing and exploring the great outdoors of Colorado.

Jeff Johnson, Vice President

Jeff joined Calcon in 2007 and is currently a Vice President of the company.

He has a Bachelor’s degree in Construction Management from CSU and brings 19 years of Project Management experience to the table.

Jeff has completed many of Calcon’s most notable builds in the healthcare industry, including: specialty medical facilities, medical office buildings and hospitals.

Jeff is a LEED Green Associate, Certified Healthcare Constructor and a member of CAHED and ASHE.

When not at work, Jeff enjoys time with his wife and two girls.

Jim Van Zant, Vice President

Jim joined the Calcon family in 1986 and has been in involved in many of our most notable builds.

Jim graduated from Colorado State University with a Bachelor of Science degree in Industrial Construction Management.

He is currently a Vice President and also serves as a Senior Project Manager. He handles pre-construction, estimating and project management for Calcon’s projects, seeing them through construction, closeout and warranty

Jim presently serves as Treasurer and on the Board of Directors for the Construction Industry Training Council (CITC), which offers apprenticeship programs for the construction trades.  He is also a member of the American Society for Healthcare Engineering and has received their Healthcare Contractor’s Certificate.  He has served as an instructor for a project management class offered by Associated General Contractors.

When not in the office, Jim enjoys the outdoors, his family and his ever growing motorcycle collection.


Our History

A story of excellence

We Build: With Colorado’s Communities at Heart

In 1981, Calcon Constructors, one of Colorado’s leading commercial construction companies, first opened its doors.

Calcon was founded by Calhoun “Cal” Cox Jr. and Jim Bosshart (the current chairman).

Over the last four decades, Calcon Constructors has built more than 21 million SF of space. This has included some of Colorado’s most recognizable and beloved fixtures, such as the Daniel L. Ritchie Wellness and Sports Center at the University of Denver, the Winter Park Express Ski Train Platform and the Denver Curling Center- the first of its kind west of the Mississippi.

We are proud to be part of Colorado’s construction community. From day one, Calcon has consistently applied integrity, innovation, and insight throughout our business practices, enabling the company and community to thrive.


Philanthropy is a huge part of Calcon’s core values; we believe local companies should support all aspects of their communities.

Since its inception, Calcon has donated millions of dollars to local charities. We believe healthy communities equal healthy companies.

“Calcon Constructors and I have been very fortunate. I am indebted to all employees of Calcon. We could not have accomplished our successes in business without having worked with world-class building owners, design professionals, subcontractors and suppliers. We have provided safety, quality, value, honesty, respect and responsibility for our owners, designers and construction team. I am proud of every project Calcon has ever done.”
– Cal Cox, Founder.


“Our goal is not to be the largest general contractor in Colorado— just the finest.”


2007 AGC National Construction Safety Excellence Award

Pinnacol Safety

2011 Pinnacol Circle of Safety Award


2012 AGC National Construction Safety Excellence Award


2015 AGC Colorado Zero Incidence Rate Safety Award


2016 Bronze AGC Ace Award for “Best Project” ($10 Million – $40 Million)

Let’s build a better Colorado together.

Contact the Colorado construction experts at Calcon today to turn your construction dream into a reality.



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