Robert L. Sisk (Bob, age 79) passed away at home on Tuesday, July 15, 2025. He was born on September 19, 1945, in Spearfish, to Charles & Susan Sisk.

The avid outdoorsman graduated from Spearfish High School in 1964. Bob served 2 years (1967-1969) in the Army as a Missile Survey Specialist.

He returned to Spearfish to enroll in Black Hills State University in 1973. Bob received a Bachelor of Science degree and was ready to teach biology. For the next 27 years, students in Martin, Philip, and Newell benefitted from his knowledge and enthusiasm.

Bob helped students enjoy science because he shared their curiosity. He listened to their questions and shared his stories. He gave students time to think, and time to discover and experiment. Bob's lessons extended far beyond the realm of science.

In 1986, Bob married fellow teacher, Jan (Rainey) Tysdal. Bob's Biology and Jan's English worked well together. The couple wrote and published four natural history books in retirement and shared a lifetime of adventures!

Bob is survived by his wife of 38 years, Jan; brother, Stephen; son, Andrew Sisk and family; Sarah, Marne & Luke Tysdal and families. Over the years, several grandchildren entered the picture. He was preceded in death by his parents, Charles & Susan Sisk; his sister, Judy and his brother, James.