Tourism is one of the main drivers of economy in Darjeeling and therefore it is obvious that there will be plenty of tour operators & agents. Many of them are specialized in the area of adventure tourism including treks & hikes, and some even offer white water rafting, mountain biking and other activities along with gears & equipment.
Offering tours has become one of the common & easy occupations in Darjeeling. While this can be a great advantage for tourists, the flip side is some very low quality operators have also come into play. In my section below, I have tried to review the well known operators in Darjeeling who have been providing services for the last several years and have done well so far. My evaluation is based on the quality of guide, the vehicle, the equipment and the gears they provide for the tours and adventure activities.
Adventure Trek & Tour Operators 
The following operators of Darjeeling are specialized in adventure tours like treks, white water rafting, mountain biking, paragliding, sportss rock climbing etc.