Gregory 3D Hydro Trek Hydration Reservoir - 3 Liters

Color: Optic Blue
Size: 3 L
Shipping restrictions apply.

Members get an estimated $5.50 (10%) back on this item as a part of your annual .

Members get an estimated $5.50 (10%) back on this item.
To buy,  sign in as an REI Co-op Member or join now.

The Gregory 3D Hydro Trek hydration reservoir transitions easily from trail sipping to camp water station thanks to its pour spout. Its multi-position design can fit in the top or sleeve of your pack.

Location Image of color Optic BlueLocation Image of color Optic BlueLocation Image of color Optic Blue
Location Image of color Optic Blue


  • Soft-molded 3D reservoir design prevents contact between top and bottom layers, speeding up drying time and discouraging bacteria growth
  • Heavy-duty construction with increased film thickness adds durability compared to standard hydration reservoirs
  • Round shape is designed to fit at the top of your pack and in traditional hydration sleeves; wider body distributes weight high and tight when secured on top with a drawstring
  • Push-button pour spout creates a basecamp tap with a fast water flow and less spillage when filling pots or hand-washing dishes
  • Molded dust cover protects the pour spout from dirt and grime on the trail and provides worry-free storage
  • Molded hanger loop with a reflective webbing strap makes it convenient to set up your camp's water station or easy to hang dry an empty reservoir
  • A soft-molded handle on the spine makes filling easy; the co-molded baseplate provides full-length support for hassle-free insertion and removal from the pack
  • Integrated, 90° quick-disconnect fitting enables smooth hose routing and quick removal of the reservoir
  • Standardized quick-disconnect fittings integrate with any filtration system for on-trail water filtration that's easily accessible from the top of your pack
  • EasyGrip rubberized fill port allows for easy opening and filling; compatible with 38 mm pump filters
  • Lever action on/off bite valve with magnetic clip allows for confident, leak-free storage while traveling to and from the trail (magnet accessory included)
  • SpeedClip mounting system offers one-handed, lock-and-go linkage between the reservoir hanger and most full-size day packs


View all Gregory Reservoirs

Technical Specs

Best Use


Liquid Capacity (L)

3 liters

Liquid Capacity (fl. oz.)

101.4 fluid ounces

Bite Valve Shut-off Switch


Wide-Mouth Opening


Quick Disconnect Tubing



Metallocene PE film (BPA- and PVC-free)


12.4 x 9.44 x 3.15 inches

BPA Free



13 ounces

14 reviews with an average rating of 4.2 out of 5 stars

Loading Reviews...

Questions & Answers

Loading Questions...