Become a Member

Your membership pays itself back through discounts on products, access to exclusive resources, and educational opportunities.
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.
Register Online

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


Congratulations to our TCC Overall Champions, Andrew Dunavant and Jocelyn Lohse! For full results go to our Tree Climbing Championship page.

Nationals Ballpark Outing (Sold Out)

MAC-ISA is hosting a group outing on Saturday night, July 29th, from the ISA Conference at National Harbor to Washington Nationals vs. Colorado Rockies baseball game at Nationals Ballpark. Price ($55) includes a gallery seat and round trip transportation from Gaylord Convention Center, National Harbor. 

2017 ISA Annual Conference Registration is now open!

2017 ISA Annual International Conference: 28 July–2 August: One World Under One Canopy Registration is now open! View registration options, and register online by 2 June 2017 for lowest registration rates. The 2017 ISA conference location and host hotel is the Gaylord National Resort & Convention Center in Washington, DC, USA. The deadline to reserve a room in the ISA block at the host hotel is 1 July 2017. See hotel reservation information, and watch for information on additional hotels, available soon.

Registration Open for Many Events

Registration is available for our   Certification courses and TRAQ course.

Volunteers Needed

Volunteers are needed for the 2017 ISA International Conference and Arbor Fair, please contact This email address is being protected from spambots. You need JavaScript enabled to view it..

Bonnie Appleton Memorial Fund Update

HELP US REACH OUR FUNDRAISING GOAL OF $100,000 to endow this scholarship. We need your help to finish our goal! Please donate. Donate to the Bonnie Appleton Memorial Fund and MAC-ISA will match 100% of your tax deductible gift, up to a total of $4,500. Read more on the Tree Fund page under the Bonnie Appleton Fund section.


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