Athlete tackling El Capitan, e.g.

ROCK CLIMBER

This person might use chalk and carabiners while scaling sheer vertical surfaces, often found in national parks like Yosemite.

This clue plays on the double meaning of "tackling"—both as a sports term and as taking on a challenge. "El Capitan" is a famous rock formation in Yosemite, so someone "tackling" it would be a rock climber, not a football player. The "e.g." hints that this is just one example of the broader answer.