[3][4][5] The area is popular with hikers, campers, cyclists, and whale watchers although biking and camping on the mountain itself are prohibited.

[3][7][8] Humbug Mountain was created about 130 million years ago, in the early Cretaceous period.

[9][10] It was formed when islands in the Klamath microcontinent collided, uplifting primordial mountains composed of mostly sandstone.

Then, the microcontinent collided with the North American continent, uplifting Humbug Mountain in the process.

[14][15] In 1934 the Civilian Conservation Corps built the first trail to the summit, however, it was destroyed in the 1962 Columbus Day Storm.

The most common types of trees include tanoak, Douglas fir, big-leaf maple, Port Orford cedar, and Oregon myrtle.

[17] Smaller plants such as maidenhair ferns, wild rhododendrons, and vanilla leaf are abundant in the area.

The trail to the west was originally built in 1934 by the Civilian Conservation Corps, but was washed out in the Columbus Day Storm of 1962.

[3][4] Another trail leads from the campground, under the highway, to a 4-mile (6.4 km) long beach on the north side of the mountain.

It is approximately 2.6 miles (4.2 km) long, and crosses nearby Brush Creek seventeen times.

[4][7][12][18][21] Nature study, wildlife viewing, camping, and whale watching are popular activities around the mountain.