| Company |
City |
State |
| Macalester College | St. Paul | Minnesota |
| MACTEC Engineering and Consulting, Inc | Golden | Colorado |
| Magnuson Consulting | Seattle | Washington |
| Maine Conservation Corps | Augusta | Maine |
| Maine Department of Conservation | Augusta | Maine |
| Mangi Environmental Group | McLean | Virginia |
| Manice Education Center | Florida | Massachusetts |
| Maria Mitchell Association | Nantucket | Massachusetts |
| Maricopa County | Phoenix | Arizona |
| Marin Conservation Corps | San Rafael | California |
| Marin Conservation Corps | San Rafael | California |
| Marin Conservation Corps | San Rafael | California |
| Marine Environmental Research Institute | Blue Hill | Maine |
| Marine Science Consortium, Inc. | Wallops Island | Virginia |
| MarineLab | Key Largo | Florida |
| Maryland Department of Agriculture | Annapolis | Maryland |
| Maryland Environmental Service | Millersville | Maryland |
| Maryland Environmental Service | Millersville | Maryland |
| Maryland Motor Vehicle Administration | Glen Burnie | Maryland |
| MASCO Corporation | Taylor | Michigan |
| Mason, Bruce & Girard, Inc. | Portland | Oregon |
| Mason, Bruce & Girard, Inc. | Portland | Oregon |
| Massachusetts Department of Environmental Protection | Boston | Massachusetts |
| Massachusetts Institute of Technology | Cambridge | Massachusetts |
| MassPIRG | Boston | Massachusetts |
| Matrix New World Engineering, Inc. | East Hanover | New Jersey |
| Matson and Associates | State College | Pennsylvania |
| Mattole Restoration Council | Petrolia | California |
| Mayan International | London | International |
| MBC Applied Environmental Sciences | Costa Mesa | California |
| MBC Applied Environmental Sciences | Costa Mesa | California |
| McDonough Braungart Design Chemistry | Charlottesville | Virginia |
| McDowell Environmental Center | Nauvoo | Alabama |
| McHenry County Conservation District | Woodstock | Illinois |
| McLane Environmental, LLC | Princeton | New Jersey |
| Mecklenburg County Park and Recreation | Charlotte | North Carolina |
| Megdal & Associates | Acton | Massachusetts |
| Mesa,City of | Mesa | Arizona |
| METCO Environmental, Inc. | Addison | Texas |
| Michaels Wilder | Peoria | Arizona |
| Michelin | Greenville | South Carolina |
| Michigan State University | East Lansing | Michigan |
| Michigan State University | East Lansing | MI |
| Microecologies, Inc. | New York | New York |
| MidAmerican Energy | Des Moines | Iowa |
| Middle Rio Grande Conservancy District | Albuquerque | New Mexico |
| Middlebury College | Middlebury | Vermont |
| Milian, Swain & Associates | West Palm Beach | Florida |
| Miller Advertising | New York | New York |
| Minnesota Conservation Corps | Maplewood | Minnesota |
| Mississippi Gulf Coast Community College | Perkinston | Mississippi |
| Missouri Department of Natural Resources | Jefferson City | Missouri |
| Montana Department of Environmental Quality | Helena | Montana |
| Montana Department of Environmental Quality | Helena | Montana |
| Monterey Bay Aquarium | Monterey | California |
| Moore & Van Allen PLLC | Charlotte | North Carolina |
| Morro Group, Inc. | San Luis Obispo | California |
| Mount Holyoke College | South Hadley | Massachusetts |
| Mountains to Sound Greenway Trust | Seattle | Washington |
| Mountains to Sound Greenway Trust | Seattle | Washington |
| MPM & ASSOCIATES | Mission Viejo | California |
| Murray and Downs AIA Architects, Inc. | Placerville | California |
| MWH Global | Broomfield | Colorado |
| Myrick Hixon EcoPark | La Crosse | Wisconsin |
