Mark Walter Klausner, 76, of Galena, IL, passed away peacefully at his home on Friday, August 8, 2025.

Born on May 12, 1949, in Chicago to Felix and Irene (Galin) Klausner, Mark graduated from Marian Catholic High School in Chicago Heights in 1967, where he excelled as a varsity football player and wrestler. He earned a Bachelor of Science in Business Administration from Northern Illinois University in 1971 and an MBA from St. Ambrose University in 1998. On August 15, 1970, Mark married Kathleen Patricia Klausner (née Hunter) at St. Gerard Majella Catholic Church in Markham, IL.

He grew up in Riverdale, IL, and later raised his family in Aurora, IL. Mark was an Eagle Scout and cherished time spent golfing, boating, woodworking, attending sporting events, and playing poker with his brothers, sons, and nephews. Mark and Kathy enjoyed traveling together, with cruising being his favorite way to see the world. A lifelong Chicago Cubs fan—despite growing up on the south side, Mark was thrilled to witness the Cubs winning the World Series. He was a dedicated and successful businessman, owning and operating several area businesses, most notably Eagle Ridge Resort and Spa in Galena.

Mark is survived by his beloved wife, Kathy; his six children: Mark Klausner, Amy (Damon) Sealock, Matthew Klausner, Beth (Brad) Elstad, Megan (Brandon) Weis, and Erin (Bear) Wegener; and ten grandchildren: Connor Solfisburg, Madison Weis, Cassidy Sealock, Austin Weis, Gavin Klausner, Ethan Sealock, Grant Klausner, Charlie Wegener, Keelin Wegener, and Delaney Elstad.

He was preceded in death by his parents and his brother, Paul Klausner.

A Mass of Christian burial will be held at 11 AM on Thursday, August 28, 2025, at St. Mary’s Catholic Church in Galena. Following the mass, a Celebration of Life will take place at Eagle Ridge Resort & Spa (444 Eagle Ridge Drive, Galena, IL) until 3 PM, with a share time starting at 1:15 PM. The burial of his cremated remains will occur later. The Furlong Funeral Chapel in Galena is assisting the family.

Donations can be made to Hospice of Dubuque at https://hospiceofdubuque.org/donation

Online condolences may be left for the family at www.furlongfuneralchapel.com.