ULA Catalyst vs Gossamer Gear Mariposa 60
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).
| Spec | ULA Catalyst | Gossamer Gear Mariposa 60 |
|---|---|---|
| Price | $300 | $315 |
| Rating | 4.8★ (400) | 4.7★ (450) |
| Type | Ultralight Pack | Ultralight Pack |
| Frame Type | Internal Frame | Internal Frame |
| Capacity | 75 L | 60 L |
| Weight | 2.65 lbs | 2.16 lbs |
| Max Load | 40 lbs | 35 lbs |
| Torso Fit | S: 15-18 in, M: 18-21 in, L: 21-24 in | Sized S-L, 14.5-21.5 in |
| Material | ULA 400 Robic nylon | 100D/200D Robic nylon |
| Back Panel | Foam panel with carbon-fiberglass hoop and dual stays | Removable sit-pad with aluminum stay |
| Adjustable torso | No | No |
| Ventilated back | No | No |
| Raincover included | No | No |
| Hipbelt pockets | Yes | Yes |
| Removable lid | No | No |
| Hydration sleeve | Yes | Yes |
| Fits BV500 bear can | Yes | Yes |
| Warranty | ULA lifetime against defects | Gossamer 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.

