Basecamp Explorer
   Showcases worldwide destinations and philosophy. Includes terms and conditions, and contact details.
   http://www.basecampexplorer.co.uk/

Crooked Trails
   Non-profit, community-based travel organization promoting study tours, and village-based cultural exchanges with indigenous peoples in South America, Asia, and Kenya.
   http://www.crookedtrails.com/

Cross Cultural Journeys
   Offers travel opportunities for individuals and groups seeking personal and global awareness.
   http://www.crossculturaljourneys.com/

Discovery Initiatives
   London agency offers unique holidays, including walking the wilderness trail and wildlife conservation programs.
   http://www.discoveryinitiatives.co.uk/

Dolphin Charters
   Rates and schedules for small group wildlife and photography cruises in southeast Alaska, California, Baja, British Columbia, Mexico, the Galapagos and San Francisco.
   http://www.dolphincharters.com/

DreamWeaver Travel Company
   Presents itineraries, guidelines, and travel ethics for guided tours to West Africa and South America.
   http://www.dreamweavertravel.net

Earth Routes
   Provides worldwide destination and project information with links to travel advisories and home exchange opportunities.
   http://www.earthroutes.net/

Eco Trail
   UK based operators of marine, mammal, and birding tours in Sri Lanka and Brazil.
   http://www.ecotrail.co.uk/

EcoVentures Nature Tours and Travel
   Offering guided small group tours and customized tours for individual travelers.
   http://www.ecoventures-travel.com/

Ecotourism Activity Guide
   Information on ecotourism with links to associated activities and organizations.
   http://www.ecotourism-activityguide.com/

Ecotourism at Conservation International
   Presents listings of organisations and destinations worldwide.
   http://www.ecotour.org/

Ecotrackers Foundation
   Non-profit organization of international volunteers and students working to preserve the cultural and biological diversity of Ecuador.
   http://www.ecotrackers.com/

Ecotravel.com
   On-line magazine with directory of operators, lodges, private guides, organizations, and ancillary travel services..
   http://www.ecotravel.com/

Ecovolunteer
   Information for travellers volunteering to participate in environmental projects worldwide.
   http://www.ecovolunteer.de/

Environmental Adventure Company
   Itineraries and guide profiles for wildlife and cultural travel experiences in North and South America.
   http://www.eactours.com

Exotic Worldwide Adventures
   Ecotours in Venezuela and the Western United States.
   http://www.exoticwadventures.com/

Fischer Outdoor Discoveries
   Offers wildlife tours of Yellowstone and Glacier National Parks, Alaska, and Botswana, with news and testimonials.
   http://www.fischeroutdoor.com/

Footloose Forays
   Selection of small group educational trips into the natural world, from day trips to three week adventures.
   http://www.footlooseforays.com/

Global Research on Wildlife
   Offers hands-on research and conservation experience and training with expert biologists.
   http://www.wild-expeditions.co.uk/

Green Travel Network
   Yahoo groups forum with focus on sustainable tourism.
   http://groups.yahoo.com/group/green-travel/

Greentours Natural History Holidays
   UK based company offers worldwide natural history tours.
   http://www.greentours.co.uk/

Hosking Tours
   Details and itineraries for photographic tours and safaris to a range of destinations.
   http://www.hosking-tours.co.uk/

International Wildlife Adventures
   Offering trips around the world to observe and photograph wildlife including polar bears. Led by professional photographers and naturalists.
   http://wildlifeadventures.com/

Journeys International, Inc.
   With more than 300 eco-trips to 45 worldwide destinations for nature and culture explorations.
   http://www.journeys-intl.com/

Kalahari Management Inc.
   Information and consultancy for the ecotourism industry.
   http://www.kalahari-online.com/

La Hesperia
   Volunteer working programs at La Hesperia biological station and cloudforest reserve in central Ecuador. Includes requirements and conditions, rates, FAQ, and program details.
   http://www.volunteersecuador.com/

Lindblad Expeditions
   Provider of small ship cruises presents itineraries, schedules, prices, and daily expedition reports.
   http://itins.expeditions.com/

Manaca Ecotravel
   Offers worldwide tours. Includes destination details with ecological assessment ratings.
   http://www.manaca.com/

Moloney Hand-Built Trips
   Personally guided wildlife expedtions worlwide.
   http://www.moloneytrips.com/

Naturetrek
   Selection of international tours, treks and cruises guided by British naturalists.
   http://www.naturetrek.co.uk/

New Jersey Audubon Society
   Information on North American and International Eco-tours focused on birds and other wildlife.
   http://www.njaudubon.org/Travel/

One World Journeys
   Offering expeditions dedicated to connecting people with the planet. Includes schedules, past journeys, and environmental articles.
   http://www.oneworldjourneys.com/

Planeta.com
   Virtual library archiving more than 8,000 pages about ecotourism and conservation. Includes contacts and bibliographies.
   http://www.planeta.com/

Reef and Rainforest
   Offers educational family adventure holidays worldwide.
   http://www.familytours.co.uk/

ResponsibleTravel
   Ethical travel resource providing information about the environmental impact of tourism, respect for local cultures and laws, photography, and banned souvenirs.
   http://www.responsible-travel.org/

Sustainable Travel International
   Non-profit organization that supports and promotes ecotourism, through education and outreach. Includes employment opportunities and programs.
   http://www.sustainabletravelinternational.org/

The Original Canopy Tour
   Offers information for canopy tour companies in seven international locations. Includes photos and booking information.
   http://www.canopypago.com/

Tours of Exploration
   Offers soft adventure, birdwatching, wildlife viewing, natural history, culture, and ecotourism programs worldwide
   http://www.toursexplore.com/

Travelroots
   Presents destination information for responsible, ecologically sustainable holidays worldwide with useful links and tips.
   http://travelroots.com/

Voyage of the Wanderbird
   Operates long distance sailing cruises that provide informal education and interactive wildlife research projects.
   http://www.wanderbirdcruises.com/

WildWatch Tours
   Offer escorted wildlife and photographic tours. Includes destination information, guide profile, and enquiry form.
   http://www.wildwatchtours.co.uk/

Wildspace Expeditions
   Personalised Indian and African wildlife tours catering to small private groups.
   http://www.wildspace.biz/

World Primate Safaris
   Presents destination and accommodation options, suggested itineraries, terms and conditions, and contact details.
   http://www.worldprimatesafaris.com/

Worlds Together Travel Network
   Immersion travel and cultural opportunities in Jamaica, Dominica Republic, Belize, and Egypt. Includes destination information and trip reports.
   http://worldstogethertravel.com/