ULA Catalyst vs Gossamer Gear Mariposa 60
Quick take: The Gossamer Gear Mariposa 60 costs $4.99 less; the ULA Catalyst carries more (75 vs 60 liters); the Gossamer Gear Mariposa 60 is lighter (2.14 vs 2.78 lbs).
Which one to buy
Capacity or organization: that's the choice between two packs $5 apart. The ULA Catalyst holds 75 L and is rated at 40 lb on dual aluminum stays plus a hoop. The rating is honest: desert hikers carry 8 liters of water without collapse, and owners buy it to fit a BV500 horizontally with about 10 days of food around it. The Gossamer Gear Mariposa 60 holds 60 L, is rated at 35 lb on a single aluminum stay, and past 35 lb that stay starts to twist. It's an organized ultralight pack, not a hauler.
The Mariposa's case is its pockets. Seven of them are arranged so that fans say they open the main bag about twice a day, and the tall side pocket holds a whole tent away from dry gear. Its back pad pulls out as a camp sit pad. A BV500 also fits horizontally at the top of the bag, which many 60 L ultralight packs can't manage. The trade-offs: the asymmetric layout takes practice to balance, the hipbelt foam softens over a full thru-hike, and Gossamer Gear's warranty runs one year against ULA's lifetime coverage.
The Catalyst's catch is that its size is easy to overbuy. Its own owners say buyers who don't need the volume usually wish they'd bought the smaller ULA Circuit, and the big collar gets floppy when the pack is underfilled. If your trips mean 8-10 day food carries, winter kit or a canister plus a packraft, it's the right tool.
Neither breathes well. Both foam backs soak a shirt on humid climbs, and both use fixed torso sizes bought online, so measure carefully. The Mariposa's independently sized hipbelt gives it a slightly more custom fit.
ULA Catalyst
For long food carries, winter trips and canister-plus-packraft loads where you need 75 L and an honest 40 lb carry.
Gossamer Gear Mariposa 60
The better fit for thru-hikers whose loads stay at or under 35 lb and who want every item reachable without opening the main bag.
| Spec | ULA Catalyst | Gossamer Gear Mariposa 60 |
|---|---|---|
| Price | $319.99 | $315 |
| Rating | — | — |
| Type | Ultralight Pack | Ultralight Pack |
| Frame Type | Internal Frame | Internal Frame |
| Capacity | 75 L | 60 L |
| Weight | 2.78 lbs | 2.14 lbs |
| Max Load | 40 lbs | 35 lbs |
| Torso Fit | S 15-18 in, M 18-21 in, L 21-24 in, XL 24+ in | Sized S-L: S 16-18 in, M 18-20 in, L 20-22 in |
| Material | ULA 400 Robic nylon | 100D and 210D recycled Robic nylon |
| Back Panel | Foam panel with carbon-fiberglass hoop and dual stays | Aluminium hoop with removable SitLight foam pad |
| 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 warranty: original owner, defects in materials and workmanship (wear, accidents and misuse excluded) | Gossamer Gear one-year warranty against manufacturing defects |
Pros & cons
ULA Catalyst
- ✓The go-to answer when ultralight hikers ask '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.
- ✓About 6 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 2.78 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 100/210 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.
ULA Catalyst vs Gossamer Gear Mariposa 60: common questions
Is the Catalyst too much pack if I'm considering a Mariposa 60?▾
Often, yes. Catalyst owners say buyers who don't need the volume end up wishing they'd bought the smaller Circuit, and its collar gets floppy when underfilled. If your loads stay under 35 lb, the Mariposa's 60 L is usually enough.
Which pack handles a bear canister better?▾
Both take a BV500 horizontally. Catalyst owners fit about 10 days of food around it, while in the Mariposa it rides at the top of the bag, which many 60 L ultralight packs can't do. The Catalyst has more room left over.
Does the Mariposa 60's asymmetric pocket layout cause problems?▾
It takes practice. Balancing weight across the uneven pockets is an acquired skill and frustrates people who like symmetry. In return, the tall side pocket holds a whole tent and most gear stays reachable.