ULA Catalyst vs Gossamer Gear Mariposa 60

ULA Catalyst

ULA Equipment

ULA Catalyst

$300

4.8★ (400)

vs
Gossamer Gear Mariposa 60

Gossamer Gear

Gossamer Gear Mariposa 60

$315

4.7★ (450)

Quick take: The ULA Catalyst costs $15 less; the ULA Catalyst carries more (75 vs 60 liters); the Gossamer Gear Mariposa 60 is lighter (2.16 vs 2.65 lbs).

SpecULA CatalystGossamer Gear Mariposa 60
Price$300$315
Rating4.8★ (400)4.7★ (450)
TypeUltralight PackUltralight Pack
Frame TypeInternal FrameInternal Frame
Capacity75 L60 L
Weight2.65 lbs2.16 lbs
Max Load40 lbs35 lbs
Torso FitS: 15-18 in, M: 18-21 in, L: 21-24 inSized S-L, 14.5-21.5 in
MaterialULA 400 Robic nylon100D/200D Robic nylon
Back PanelFoam panel with carbon-fiberglass hoop and dual staysRemovable sit-pad with aluminum stay
Adjustable torsoNoNo
Ventilated backNoNo
Raincover includedNoNo
Hipbelt pocketsYesYes
Removable lidNoNo
Hydration sleeveYesYes
Fits BV500 bear canYesYes
WarrantyULA lifetime against defectsGossamer Gear limited lifetime

Pros & cons

ULA Catalyst

  • The go-to answer when r/Ultralight asks 'what if I need more than a Circuit' — same DNA, more capacity, 5 lb higher rating.
  • Dual aluminum stays plus the hoop make its 40 lb rating honest; desert hikers carry 8L of water without collapse.
  • 75 liters swallows a BV500 horizontally plus 10 days of food — the specific use case owners buy it for.
  • The same 400d Robic bombproof reputation as the Circuit, with thousands-of-miles reports common.
  • Massive front mesh and hipbelt pockets keep a full day's needs outside the main bag.
  • Hand-made in Utah, easily repairable, backed by ULA's excellent service.
  • Only 5 ounces heavier than the Circuit for 7 more liters and a stiffer frame.
  • Strong resale on trade forums, like everything ULA.
  • Overkill for standard three-season loads — most buyers who don't need the volume end up wishing they'd bought the Circuit.
  • Same zero-ventilation foam back as the Circuit; sweat is the tax.
  • Fixed torso sizes with direct-order-only sizing risk.
  • At 2.65 lbs it's approaching crossover packs with plusher harnesses.
  • The big collar is floppy when underfilled, so partial loads need diligent compression.
  • No lid, no internal organization — the usual ULA minimalism.
  • Seasonal lead times can be long.
  • The look is pure function; nobody buys a Catalyst for style.

Gossamer Gear Mariposa 60

  • The seven-pocket layout is the best organization in ultralight — fans say they touch the main compartment twice a day, morning and night.
  • The tall side pocket holds a full tent separately from dry gear, the single most-praised design choice.
  • The removable back pad doubles as a sit pad, saving carrying a separate one.
  • Robic nylon at 100/200 denier hits a durability sweet spot documented across thousands-of-miles reports.
  • Hipbelt sizing is independent of torso sizing, giving semi-custom fit from stock parts.
  • Carries 30-35 lbs comfortably with the stay in — honest rating per long-term reviews.
  • The Austin-based company's customer service and repair culture draw consistent praise.
  • Fits a BV500 horizontally at the top of the bag, which many 60L UL packs can't.
  • The asymmetric layout is polarizing — packing balanced weight takes practice and annoys symmetry-lovers.
  • The foam back pad ventilates poorly and soaks sweat on climbs.
  • The single aluminum stay twists under 35+ lb loads; it's not a heavy hauler.
  • Mesh pockets abrade in brush faster than solid-face rivals.
  • No top lid and a floppy over-the-top strap system that takes fiddling to compress well.
  • Fixed torso sizes with online-only sizing risk.
  • At $315 it's priced above the Circuit while carrying slightly worse at max load.
  • The hipbelt foam softens noticeably after a full thru-hike, per multiple finishers.