One year after her brother's death, Kristin Cavallari still holds his memory close to her heart.

The former reality star took to Instagram on Monday, where she shared an emotional, touching tribute to her late brother, Michael, who was found dead of hypothermia in the hills of Grand County, Utah, last year, days after being reported missing.

WATCH: Kristin Cavallari Opens Up About Brother's Death and Her Scary Car Accident

"Yesterday was the anniversary of my brothers passing. There hasn't been a day that's gone by where I haven't thought of him and missed him," the 29-year-old mother of three captioned a photo of Michael. "I know he is watching over me and my family though from all of the amazing signs he has given us. Love and miss you so much, Mikey."

The news of Michael's disappearance and subsequent death broke just after the birth of Kristin's third child, daughter Saylor James, with husband Jay Cutler.

WATCH: Kristin Cavallari Celebrates Daughter Saylor's First Christmas With Matching Holiday Pajamas

Back in March, the former "Hills" star spoke with ET about how she's been dealing with her painful loss, and how her newborn daughter helped her cope and heal.

"I've really found a lot of strength in my kids," she shared, adding that she "couldn't collapse" while dealing with her brother's death because she "had a newborn baby to look over."