Thursday’s ruling in Hideout’s favor reverses 4th District Court's decision.
Hideout is seeking to annex over 300 acres southeast of the Richardson Flat park and ride. The land in question is owned by Larry H. Miller Real Estate, and Hideout would like to develop a town center there.
The town began annexation in 2020, when for just over 100 days, the state legislature allowed municipalities to annex unincorporated areas without filing a petition or getting permission from the relevant county.
Hideout, which is in Wasatch County, had started to annex part of Richardson Flat in Summit County. The town made sure the annexation would be connected to the rest of its land by including a “cherry stem” of land along state Route 248.

Summit County challenged the move in court after Hideout failed to complete the annexation before the law changed again.
In 2021, 4th District Court said that fact meant Hideout couldn’t finalize its annexation.
Thursday, the Utah Supreme Court reversed the lower court's ruling. It found Summit County can’t legally oppose Hideout’s annexation.
"We fought this as hard as possible and ran it all the way to the top," Summit County Attorney Margaret Olson said in a statement. "We respect court rulings and will be evaluating the situation in coming weeks."
Hideout's town attorney did not immediately respond to a request for comment.
"We look forward to working collaboratively with our local government colleagues and community partners to meet the progressive planning goals exemplified by our regional leaders as well as to meet the critical infrastructure requirements of Hideout," Town Administrator Jan McCosh said in a statement.
Summit County was the only governmental entity opposing Hideout’s annexation, so it’s likely the town will be able to complete it. It's been about a year and a half since the parties made oral arguments at the state's high court.
Park City confirmed Hideout's proposed annexation does not overlap with Park City's 2022 annexation of western Richardson Flat.
A subsidiary of Larry H. Miller Real Estate opposed that annexation in 3rd District Court but lost. The developer has since offered to partner with Park City on affordable housing in the area.
This is a developing story.