From The Seattle Times, May 19, 1975:
From James Carey Elder II, whose parents moved to Mirrormont in 1966: It was a calm, quiet summer night before there were many houses in Mirrormont. All of the windows were open, and I was in the bathroom when I heard this terrible roar, like a lion in a TV nature show. It turned out that someone living on 152nd Street near the fire station had a caged African lion there for about a week.
From Tom Cole, who moved to Mirrormont in 1965: Where 263rd dead-ends into 152nd, there’s a house and roof are all metal. Before that, it was one of the original A-frames. The second family in there built a big, high fence to house a kennel because they raised German Shepherds. The third family who moved in there had a full-grown lion. In the summer, when that lion would roar, you could hear it all over Mirrormont. Some neighbors finally made him get rid of it.
From Erica Sargeant: The lion was young and kept in a dog run. The house was just outside the Mirrormont limits. Animal control was tasked with finding it a new home. Apparently, it was not illegal to have a lion, just to house it in a dog run.
This is the property where Mickey lived: