Columbia Boulder, Granite climbing boulder in Yosemite National Park, United States

Columbia Boulder is a 30-foot-tall (9.1 m) granite boulder in Camp 4 at Yosemite National Park, the largest boulder in the campground and easily seen from it. It holds several bouldering problems, including Midnight Lightning, Robbins Eliminate, Bates Problem and Ament Arête.

Routes on Columbia Boulder are named after climbers who established them: Royal Robbins (Robbins Eliminate), Barry Bates (Bates Problem) and Pat Ament (Ament Arête). The boulder's best-known problem, Midnight Lightning, became an early benchmark of modern bouldering. Mike Borghoff notes there are no easy problems on the 30-foot boulder.

The boulder's routes carry climbers' names: Robbins Eliminate after Royal Robbins, Bates Problem after Barry Bates, and Ament Arête after Pat Ament. From spring to autumn, climbers and park rangers meet beside the boulder about once a week to discuss issues over free coffee.

Columbia Boulder stands in Camp 4, the walk-in campground off Northside Drive in Yosemite Valley, and is easily seen from the campsites. Approach it on foot from the campground; the boulder is the largest in Camp 4. From spring to autumn, climbers and park rangers meet beside it about once a week to talk over free coffee.

Midnight Lightning, opened by Ron Kauk in 1978, is the boulder's best-known problem and one of the most famous in the world. Mike Borghoff notes there are no easy problems on Columbia Boulder, so even its simplest lines demand real effort.