25 year old American boulderer Katie Lamb has made the first female ascent of Box Therapy 8C+, in Rocky Mountain National Park, Colorado, USA.

In doing so, she becomes the first woman to climb 8C+.

Box Therapy was first established in 2018 by Daniel Woods, one of the most experienced top-end boulderers in the world. The boulder has since been repeated - and the grade confirmed - by both Drew Ruana and Sean Bailey.

The boulder sits at 10,400ft elevation, has a six mile walk in, and is overhanging by fifty degrees. Box Therapy starts on the far left of the boulder, and follows a diagonal seam for twenty feet before finishing at the top right.

A burly cut loose separates the first half of the 'micro hold' seam from the second, before the thin crack eventually reaches the lip of the boulder. Thereafter, a short section of face climbing leads to the top out.

Lamb's bouldering form this year has been clear to see, with three 8B boulders - Spectre, Chocolate Jesus, and Evil Backwards - to her name this year already, bringing her total tally to seven. Lamb logged Spectre as an 8B+ boulder, saying that it featured the 'hardest single move' she had ever done.

Spectre aside, Lamb has five 8B+ boulders to her name, making her a clear contender to join the small group of women to have climbed 8C. Instead, she skipped the grade entirely, and broke new ground not just for herself, but for female bouldering altogether.

Sharing the news on instagram, Lamb had this to say:

'A lot of my progress can be attributed to just showing up. I know where I can be, and keep coming back until I get there. It's an asset, but can make climbing less fun. Recently I've been feeling less excitement, but more joy'.

'The pieces fit together on Box and quickly it was about silencing my doubts and flipping the switch'.

'It's a headspace fed as much by days outside shooting the shit as by days alone in the mountains. I spent some time in July walking up to this meadow trying to fill my cup, and I'm pretty happy with how it turned out'.

Keenan Takahashi, who has climbed up to 8C, was with Lamb when she made the ascent. He added:

'This year it was clear that you were leveled up and ready for something harder. Box was always something we'd talked about; after the first sesh I saw you shift into execution mode, something I've only seen in a handful of the very best in the world'.

'I knew with your mental game that you'd get it done, sooner rather than later... Sure as hell earned this one! Thank you for the lessons and inspiration'.

We've contacted Lamb to ask whether she would be interested in doing an interview with us in the coming weeks.

Check out this video from two years ago of Lamb climbing one of her five 8B+ boulders, New Base Line (f8B+), in Averstal (Magic Wood), Switzerland.