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Become a Member

Attend an Event

We promote safety in all that we do. MAC-ISA provides a huge array of educational events. Click below to view all the upcoming events.
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Become Certified

Want to become a Certified Arborist or Tree Worker? Find out which of the ISA certification credentials best meet your needs.
Become Certified

Who We Are

The MAC-ISA is a trade association for arborists, urban foresters, and others involved in the caring of trees. Our mission is "to promote a culture of safety while fostering education and research that supports the care and benefits of trees." The chapter area includes District of Columbia, Maryland, Virginia and West Virginia.

Regional Map

News & Announcements

Climbing Trees is a Sport Among Arborists

Save the date for our upcoming Tree Climbing Championship (TCC) where you can watch professional arborists climb trees as a competitive sport on April 13-14, 2024 at the Crofton Country Club in Crofton, MD. Read this article about one of our chapter's national and world champion, James Earhart written by our Executive Director, Liz Buxton.

Annual Meeting

Save the date for our Annual Meeting, October 6-8, 2024 in Chesapeake, VA. See a previous year's program here!

Tree Climbing Championship Event in the News

MAC-ISA hosted the 2023 Annual Tree Climbing Championship at Morgan's Grove Park, Shepherdstown, WV. Congratulations to the 2023 Champions, Jeff Inman and Stephanie Littenberg! Read about it in the news. This article has a quote from TCC Champion, Jeff Inman! 

MAC-ISA Board of Directors Plant Tree at Rockwater Park in Observance of Arbor Day

With the support of volunteers and the Town of Culpeper, the Board of Directors planted a dogwood tree at Rockwater Park in Culpeper, Virginia on April 26th in recognition of Arbor Day. Read more.

Elizabeth Buxton is Appointed as New Director of MAC-ISA

The Board of Directors of MAC-ISA is pleased to announce that Liz Buxton has been named its new Executive Director. Liz will take over the helm from longtime Executive Director Nancy Herwig who is retiring at the end of May. You can contact Liz at This email address is being protected from spambots. You need JavaScript enabled to view it.. Read more.

2024 Events

MAC-ISA has upcoming Arborist Certification Courses, Tree Risk Assessment Qualification and Renewal Courses, and more ahead of us this year. Click here for our upcoming events. Check out the Green Industry events that we have listed near the bottom of the page as well.

Registration Open for Many Events

Registration is available for our Certification courses and TRAQ courses and TRAQ renewal courses.

Updated Guides and Guidelines for the Mid Atlantic

We have an updated Species Rating Guide & Tree Appraisal Guidelines for the Mid Atlantic Region


Safety Tips

Helmet Safety
Always wear a helmet with your chin strap buckled.
Risk Assessment
Perform a level 2 risk assessment before your climb.
Climbing Safety
Always stay on rope.
Utility Lines
Assume that all utility lines are energized.
Stay Alert
Stay alert at all times.
Protect Crew & Public
Establish a clear work zone and drop zone.
PPE Safety
Inspect and clean your PPE regularly.
Emergency Response Plan
Establish an emergency response plan prior to work.
Check Before Working
Check your equipment, surroundings and yourself prior to everyone's job.
Maintain the 4 A's
Maintain the 4 A's:  Attitude-Awareness-Action-Accountability
Command & Response
Use command and response.
Report Unsafe Behavior
Do not accept unsafe behavior (if you see something, say something).

Attend An Event

We promote safety in all that we do. MAC-ISA provides a huge array of educational events. Register for one of our events today!

Tree Fund
International Society of Arboriculture
Trees Are Good