Climate Change & More Attorney · Serving Washington, DC · 30+ Years Experience
Profile Summary
About Mark A. Sullivan at a Glance
Mark A. Sullivan is a environmental, government, energy, and international attorney based in Washington, District of Columbia. They have 30+ years of legal experience, licensed to practice since 1996. Admitted to practice in New York (1996) and District of Columbia (1998). Educated at Yale Law School (JD, 1976). Serves clients in Washington, DC and the surrounding metropolitan area.
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About Mark A. Sullivan
- Mr. Mark A. Sullivan is a lawyer practicing energy & utilities, climate change, project finance and 2 other areas of law
- Mark has been licensed for 30 years
- Mark practices in Washington, DC
Practice Areas Explained
Mark A. Sullivan's Areas of Legal Practice
Each practice area below reflects the types of cases Mark A. Sullivan handles, with a practical overview of what that area of law involves and how it may apply to your situation in Washington.
Environmental Law in Washington
Environmental attorneys for regulatory compliance, contamination, land use, and natural resource law.
Mark A. Sullivan is one of 55,977 environmental attorneys indexed nationally. Browse environmental attorneys in District of Columbia →
Government & Administrative Law in Washington
Attorneys for administrative law, agency hearings, government contracts, licensing, and public benefits.
Mark A. Sullivan is one of 131,162 government attorneys indexed nationally. Browse government attorneys in District of Columbia →
Energy & Utilities Law in Washington
Energy attorneys for oil & gas, renewables, utility regulation, and energy sector transactions.
Mark A. Sullivan is one of 35,985 energy attorneys indexed nationally. Browse energy attorneys in District of Columbia →
International Law in Washington
International law attorneys for cross-border transactions, trade, foreign investment, and treaties.
Mark A. Sullivan is one of 39,787 international attorneys indexed nationally. Browse international attorneys in District of Columbia →
Jurisdictional Context
Why Local Counsel Matters in Washington
Practicing law in District of Columbia. Legal matters in District of Columbia are governed by state-specific rules of civil and criminal procedure, statutes of limitations, and substantive law. Cases originating in Washington are typically filed in the local municipal court or the appropriate District of Columbia state district court, depending on subject matter and amount in controversy. An attorney licensed in District of Columbia brings working knowledge of local procedural deadlines, judicial practices in this venue, and the substantive law that applies to cases brought here. Out-of-state attorneys generally cannot represent clients in District of Columbia courts without local counsel or pro hac vice admission.
Washington Courts and Legal Process
Choosing a Washington-based attorney means your counsel already knows the local docketing timelines, preferred filing formats, and how individual judges typically rule on procedural motions — details that only come from practicing in this jurisdiction day after day. That local familiarity can translate to better strategy, faster filings, and fewer costly surprises.
Looking for additional District of Columbia attorneys? Browse all attorneys in Washington or all attorneys in District of Columbia.
Frequently Asked
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Professional Profile
Why Clients in Washington Choose Mark A. Sullivan
Selecting an attorney is one of the most consequential decisions you can make when a legal matter arises. Below are the core qualities that distinguish Mark A. Sullivan's practice in the field of environmental, government, energy, and international.
Decade-Tested Legal Experience
Mark A. Sullivan brings 30+ years of hands-on legal practice — enough to have navigated the recurring fact patterns, procedural traps, and negotiation dynamics that shape case outcomes.
Multi-State Bar Admission
Licensed in New York and District of Columbia, Mark A. Sullivan can represent clients in cases that span state lines or require counsel in multiple jurisdictions.
Broad Practice Area Coverage
Covering environmental, government, and energy, Mark A. Sullivan can address the full spectrum of a client's legal needs without requiring referrals to separate specialists for each issue.
Local Presence in Washington
A Washington-based practice means Mark A. Sullivan attends hearings in the same courthouses, knows the local clerks, and understands the unwritten scheduling norms that affect every case filed here.
Search Reference
How People Find Mark A. Sullivan Online
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Mark A. Sullivan's Practice Areas & Specializations
Education & Law School Background
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