(CNN)A service dog is believed to be the first to reach the summit of Mount Rainier.
The medical alert dog, Loki, made the trek with its owner, Elizabeth Briggs. They were joined by Mel Olson and McKenzie Johnson, who led the journey. This was Johnson's seventh Rainier summit.
This particular climb has been two years in the making, starting when Johnson and Briggs met.
"The topic of climbing Rainier came up almost immediately after we met and the idea intrigued me," Johnson said. "Though I knew it would take more planning and education than the usual trip up Rainier, it was something I wanted to help them do."
In the last two years, Johnson, Briggs and Loki have spent time hiking, ice climbing, and completing a winter Colorado "14-er" (a mountain peak exceeding 14,000 feet) to prepare to take on Rainier.
"This gave me an opportunity to see Loki in his natural element and how the two of them performed together," said Johnson. "Prior to Rainier, Loki had completed 80 '14-er' summits, which often included more technical scrambles, extreme exposure, and even roped ascents."
This was their second attempt at conquering the summit. Last year, Johnson and Briggs made their first attempt, but their plans were derailed due to a storm and sickness.
Park rangers told the hikers there was no previously recorded Rainier summit made by a service dog on file.
"It's pretty awesome if Loki was the first," Johnson said.
In addition to Loki, a pineapple was along for the climb. Johnson works for The Leukemia and Lymphoma Society and is the campaign manager for a fundraiser called the Winter Pineapple Classic. Her mother has blood cancer and, as a reminder of what cancer patients go through, she brings a pineapple on some of her major summits.
Climbing the almost nine miles with a heavy pineapple in her pack was "nothing compared to what my patients or my mom or people I fundraise for go through," Johnson told CNN.
"It's just another weird thing. We had a dog and a pineapple."