There will be two opportunities this summer to learn about the geologic history of Sierra Nevada range.

Former NASA Apollo geophysicist Al Graf will explain the region’s geology and how it impacts the natural history and more. The event starts with an evening video and slide show presentation, followed the next morning by an auto tour to geologic sites near Hope Valley.

Dates are July 26-27 and Aug. 23-24. The evening show is from 7-8:30pm, with the tour the next day from 9am-noon.

Cost is $60 for guest of Sorensen’s, $95 for others. It includes lunch. Call 530.694.2203 to make a reservation.