Lisa Mahoney, President

Lisa Mahoney is the President and Owner of The Clark Group.  Over the past twenty years, Ms. Mahoney has served as a NEPA expert in both the government and private sector. As president and owner of The Clark Group, she manages the company’s environmental practice and provides clients with environmental compliance, policy, and regulatory development under NEPA and related laws and Executive Orders. Her background as both an ecologist and attorney provides her with a unique understanding and experience on how to develop and implement strategies for environmental compliance.  Ms. Mahoney previously served as Chief of Environmental Programs for the Department of Homeland Security’s US-VISIT Program and as an agency representative to the White House Council on Environmental Quality. Early in her career, Ms. Mahoney worked for the Department of Justice as an environmental protection specialist. Ms. Mahoney lives in Montpelier, VT, where she is affiliated with several Vermont-based organizations such as the Vermont River Conservancy, Vermont Environmental Consortium and the Natural Resources Committee of EnVision Montpelier.  She is a member of internationally-focused environmental organizations such as the International Association for Impact Assessment, and has served as Co-Chair of the Environmental Policy Committee for the National Association of Environmental Professionals. Ms. Mahoney earned a Juris Doctor and Master’s Degree in Environmental Law from Vermont Law School, and a Bachelor of Science degree in Ecology at Tulane University. Email Ms. Mahoney at:

Holly Reuter, Associate

Holly Reuter is an Associate located in Washington, D.C. Ms. Reuter specializes in the development and implementation of environmental and natural resource compliance strategies, analyses, regulations, policies and procedures. In particular, Ms. Reuter has extensive experience in regulatory and policy implementation, including development of ancillary guidance, training, memoranda of understanding, white papers, and outreach and communication materials. Ms. Reuter’s practice has a strong foundation in NEPA, but also includes implementation of other environmental requirements including Section 7 of the ESA, Section 106 of the NHPA, CWA, CZMA, CBRA, RCRA, EO 12898, EO 11988 and EO 11990, and the Federal Flood Risk Management Standard. Ms. Reuter has served as Project Manager for clients such as the Environmental Protection Agency, Overseas Private Investment Corporation, and Federal Emergency Management Agency. Prior to joining The Clark Group, Ms. Reuter served as a law clerk to the Council on Environmental Quality. She has a law degree from the University of Houston Law Center. Email Ms. Reuter at:


Catherine Coteus is an Associate located in Montpelier, Vermont with a strong background in environmental law and policy, program/system design, and strategic communications. Her areas of expertise include communications, environmental policy, community-based social marketing, and governmental affairs. Mrs. Coteus has experience managing programs, navigating complex environmental regulations and providing environmental technical assistance. Mrs. Coteus holds a J.D. from Northeastern University and a Master's of Environmental Law and Policy from Vermont Law School. Mrs. Coteus also received her Bachelor's in Environmental Science and Policy from Hampshire College. She also sits on the Boards of the Fairbanks Museum & Planetarium. Email Mrs. Coteus at:

Victoria Gartman, Associate

Victoria Gartman is an Associate located in Washington, DC. Ms. Gartman has detailed expertise in environmental policy and regulations with NEPA, CWA, ESA, and the MBTA as well as proficiency in EO11988, EO11990, NHPA, CZMA, and CBRA. Prior to joining TCG, she was an environmental specialist with the Federal Emergency Management Agency providing technical assistance, consultation, and outreach to impacted communities to ensure compliance with all environmental and historic preservation laws and executive orders. Ms. Gartman also conducted research in Sheffield, England and Berlin, Germany under the umbrella of international environmental assessment and planning. Her background specializes in areas of conservation biology, wildlife management, and ecological restoration. Ms. Gartman holds a Dual Master of Science in Arid Lands Studies from Texas Tech University and Humboldt University of Berlin, Germany. Email Ms. Gartman at:

Grace Vinson, Associate

Grace Vinson is an Associate located in Montpelier, Vermont. Ms. Vinson has experience in NEPA implementation and compliance, energy efficiency, stakeholder engagement, flood risk, and endangered species. Prior to joining The Clark Group, Ms. Vinson worked for the Vermont Agency of Transportation on environmental policy and legislation, including the Comprehensive Energy Plan and the Water Quality Bill. She has experience in governmental affairs, policy development and environmental law. She has also worked for the Vermont Energy Investment Corporation in the energy efficiency market. Ms. Vinson is a Certified Floodplain Manager (CFM) and holds a Bachelor of Science Degree in Environmental Studies from the University of Vermont. Email Ms. Vinson at:

Jess Wymer, associate

Jess Wymer is an Associate located in Montpelier, Vermont. She has experience in policy research and analysis, NEPA compliance, public engagement, stakeholder communications, and business operations management. Ms. Wymer joined The Clark Group after earning her Bachelor of Science degree in Environmental Studies at the University of Vermont, with a concentration in ecology and policy. While working on her undergraduate degree, she served as administrative staff for Vermont Governor Peter Shumlin and his Executive Team and as a student researcher the Vermont State House. Ms. Wymer is currently pursuing her Master’s degree in Environmental Law and Policy at Vermont Law School. Email Ms. Wymer at:

Senior Advisors

Ray Clark

Mr. Clark is one of the nation’s foremost authorities on the National Environmental Policy Act (NEPA).  His specialties include environmental analysis, military and environment and executive and legislative branch politics.  Mr. Clark is a former Acting Assistant Secretary of the Army, Principal Deputy Assistant Secretary of the Army and Associate Director at the White House Council on Environmental Quality.  He also served as Chief of the Environmental and Natural Resources Office at the U.S. Army Chemical and Military Police Schools, Fort McClellan, Alabama. Mr. Clark is the original founder of The Clark Group and is currently President at River Crossing Strategies, where he provides a wide range of services to clients, including Washington representation, strategic planning and policy development.

Horst Greczmiel

Mr. Greczmiel is a dedicated leader and environmental steward specializing in NEPA. He served as Associate Director for NEPA Oversight at the Council on Environmental Quality for over 16 years, responsible for overseeing and implementing NEPA and CEQ mandates for federal agencies, strengthening NEPA, and making NEPA implementation more effective and timely. Before joining CEQ, Mr. Greczmiel worked at U.S. Coast Guard headquarters, where he received the Commandant’s Award for Superior Achievement for environmental policy development and litigation involving species protection and environmental planning compliance. Previously, he served in the U.S. Army for 15 years, concluding with a tour in the Office of The Judge Advocate General’s Environmental Law Division and as environmental advisor to the Deputy Assistant Secretary of the Army for Environment, Safety and Occupational Health. Following his retirement in December 2015, Mr. Greczmiel has continued to engage in national policy discussions at various environmental conferences and as an expert witness at House Natural Resource Committee Hearing on NEPA. He received his B.A. from Lafayette College, J.D. from Rutgers - Camden School of Law, and LL.M. in environmental law from George Washington University, Washington, DC.


Shannon Stewart

Ms. Stewart has over 19 years of professional experience in NEPA documentation and public land issues, as well as extensive experience interpreting Federal and state environmental laws, regulations, and policies including CEQA.  She has held senior level positions in the Federal government with both the Department of Energy and the Department of the Interior specializing in complex projects and strategic policy development focused in the energy sector, and has worked in private consulting serving energy and other clients.  Shannon is a recognized leader in the field of NEPA.  She currently serves as a Board Member on the National Association of Environmental Professional (NAEP) where she chairs the NAEP Education Committee.  Shannon’s practical knowledge of NEPA and agency-specific regulations and associated guidance, as well as her longstanding relationships inside and outside of government allow her to identify effective strategies that meet client and stakeholder needs resulting in successful project outcomes.

Michael D. Smith

Michael specializes in analyzing social and community impact assessment for NEPA compliance for some of the nation's most complex and controversial projects for a wide variety of federal agencies. He is a member of the Interorganizational Committee on Guidelines and Principles for Social Impact Assessment, a group of academic and federal agency specialists that produced the most widely-used guidance document for NEPA social impact assessment procedures in the United States. In addition to over a decade of consulting experience, he is a past recipient of a Science & Technology Policy Fellowship with the American Association for the Advancement of Science (AAAS) at EPA’s Office of Water and Office of Federal Activities in Washington, DC., and was previously an Associate Professor of Environmental and Natural Resources Sciences at Humboldt State University, where he taught courses conducted research in environmental impact assessment, environmental planning, land use planning, and community development. He frequently leads training workshops in social impact assessment and environmental justice for numerous federal agencies and through several universities throughout the U.S.

Ben Taube

Mr. Taube is an experienced leader in developing cleantech companies with extensive expertise in shaping environmental partnerships, policy and education. Ben served as the founding executive director of the Southeast Energy Efficiency Alliance (SEEA), an Atlanta nonprofit aimed at implementing energy efficiency across 11 Southeast states. He has held several key posts, including as the Environmental Manager for the City of Atlanta with the responsibilities of developing and enhancing environmental initiatives and policy for one of the largest cities in the U.S. He has worked as the Director of Government Affairs for EcoSMART Technologies and as Public Affairs Manager for the GREENGUARD Environmental Institute, where he was responsible for planning, coordinating and communicating GREENGUARD’s activities, goals and priorities to a variety of audiences.

Tony Silvia

Mr. Silvia is an experienced environmental attorney and policy consultant with over ten years of experience in environmental practice.  He has worked on a wide variety of environmental and sustainability projects including environmental impact assessments for the government and private industry.  In addition, Tony is an experienced and well respected environmental law and policy instructor focusing on individualized advice regarding NEPA case law and litigation.

Juliette Searight

Ms. Searight is a highly experienced project architect, project designer, and energy consultant. She specializes in Building Envelope Analysis and Behavioral Analysis, and is currently providing consulting services for commercial and residential energy auditing. Prior to that, Juliette was a project leader, architect and designer for Gensler, a global architecture, design, planning and consulting firm, where she was responsible for developing design and coordinating construction contractors across projects at every scale, from light industrial facilities to high-end commercial and governmental. In 2012, she earned her Energy Engineering and Management Graduate Certificate.

Sarah Truckle

Ms. Truckle is an environmental consultant for project support for environmental policy issues.  Sarah holds a Juris Doctor and Master’s Degree in Environmental Law and Policy from Vermont Law School.  Prior to working with The Clark Group, Sarah served as a Google Grant Fellow for the Center of Legal Innovation where she conducted research on the policies surrounding law and technology.  Prior to that, she worked as a Human Rights Fellow for the Center for Applied Human Rights focusing on Human Rights and The Environment.  She also has experience in criminal litigation.

eric vierra

Mr. Vierra has over 25 years of experience as a graphic artist and website designer/programmer.  His specialties include information architecture, user interface design, content management administration, ADA 508-compliance of web-based content, HTML and CSS programming, desktop publishing, and brand development.

Chip Cameron

Mr. Cameron's expertise in conflict management, community outreach and interest-based negotiation strategy were developed during his tenure as the Nuclear Regulatory Commission's (NRC) Dispute Resolution Specialist under the Administrative Dispute Resolution Act and complemented by his tenure as the Assistant General Counsel at the Nuclear Regulatory Commission. He also served as the General Counsel's liaison and advisor on Tribal Law. He currently works on risk communication issues as a member of the Program Action Committee (PAC 7) on Risk Communication of the National Conference on Radiation Protection.

Lori VanBuggenum

Ms. VanBuggenum is a public health professional with over ten years of experience in program development, policy analysis and project management in university, nonprofit and for-profits settings. She has worked on environmental and sustainability projects at the nexus of agriculture and environmental sustainability including the development of metrics to measure the environmental, social and economic impact of the U.S. Dairy industry across the supply chain and relationship building among environmental and agricultural groups to advance public policy and produce environmental and public health benefits through business and program performance.

Bernadette Rigley

Ms. Rigley is a wildlife biologist with expertise in avian and bat biology and field-based research. She has an extensive background with threatened and endangered species, including compliance with ESA Section 7 and 10. She recently relocated from Southern California where she provided consulting services for a number of state and federal agencies, including CBP, USACE, FWS, and military installations. Ms. Rigley has a Master of Science degree in Natural Resource Management from Unity College and a Bachelor’s degree in Wildlife Biology from SUNY Cobleskill.