CRYSTAL LAKE – The McHenry County Conservation District offers a series of fall investigations for adults.

• Senior Explorations: 10 to 11:30 a.m. Wednesday at Pleasant Valley Conservation Area, 13315 Pleasant Valley Road, Woodstock. Participants will explore at a relaxed and leisurely pace as they witness what is happening in the prairie and woodlands during the fall season. They will identify flowers and bird species along the way. Participants should dress for the weather and walking and bring a water bottle. The program is free for county residents and $2 for nonresidents. It is for those ages 14 and older. The registration deadline is Friday.

• Century Hikers: 6:30 to 8 p.m. Sept. 10 at Prairieview Education Center, 2112 Behan Road, Crystal Lake. Participants will learn about the amazing cross-country trek made by Chicagoan Tyler Coulson, who will share what motivated him to hike across the country. The program is free for county residents and $6 for nonresidents. It is for those ages 14 and older. The registration deadline is Wednesday.