Salt Lake County has just 20 days to collect and weigh such input before recommending one site to a state committee for the ultimate determination.
In the meantime, Salt Lake County Mayor Ben McAdams has vowed to offer a "robust yet abbreviated" public process that includes two open houses and additional open meetings.
A county spokesperson said McAdams was attending to a personal matter and unavailable for comment Friday.
Legislation passed a day earlier will, if signed by the governor, empower the state's Homeless Coordinating Committee to choose a site even if it's in violation of a municipality's policies or opposed by its officials — which may be inevitable.
South Salt Lake Mayor Cherie Wood said she was "shocked and concerned." Next to Alta, her city is the county's smallest, and she said it doesn't have the tax base to support a shelter of more than 200 beds.
What's more, she said, South Salt Lake already has county jail facilities, permanent supportive housing, youth group homes and a juvenile justice center, and 10 percent of the city's residents are refugees.
Bigelow, likewise, said West Valley City is already doing its part. A city news release said its 33,000 affordable housing units are the most in the county.
He called the March 30 site selection deadline "arbitrary."
"This isn't the way that this should be done," Bigelow said, characterizing the process as "in a hurry, behind closed doors, excluding those who are going to be impacted by it."
Shaleane Gee, Salt Lake County's director of special projects and partnerships, said rather that "this is the beginning of the conversation about these locations, not the end of the conversation."
"We want to hear from [residents] what they uniquely know about their own communities and neighborhoods," Gee said.
The proposed sites are: 1820 W. Printers Row (2300 S.), West Valley City; 2411 S. Winston St. (1070 W.), West Valley City; 2249 S. Winston St. (1070 W.), West Valley City; 3091 S. Main St., South Salt Lake; and 1144 W. 3300 S., South Salt Lake.
One thread between them is proximity to transit that links the sites to Salt Lake City's associated services. Three are along the Jordan River, and none is in a predominantly residential area.
West Valley City employees had tried to guess at potential sites and had scouted all three that the county selected, said Nicole Cottle, the city's community and economic development director.