Professor Frank DeCourten is giving a lecture one day and leading a hike the next about the volcanic rocks in the Lake Tahoe region.

He plans to reconstruct the volcanic history of the area in non-technical terms.

The Aug. 6 hike will provide opportunities to directly explore the volcanic rocks and landscape features along the portion of the Pacific Crest Trail between the trailhead on Old Highway 40, through the Sugar Bowl ski area and along the Judah Loop to Roller Pass.

The lecture is Aug. 5 at the Olympic Village Lodge, Squaw Valley. No-host bar social hour begins at 6:30pm, with the program at 7pm.

It is free for Squaw Valley Institute members, $10 for others.

The hike begins at 8:30am at the Pacific Crest Trailhead parking area off Old Highway 40 (Donner Pass Road). The fees are the same as the lecture.

Space is limited. Tickets may be purchased online.