Salt Lake City ranked second among major U.S. cities, behind No. 1 Minneapolis-St. Paul. Miami ranked last.
Nationally, the volunteer rate fell in 2007 for the second year in a row, to 26.2 percent, according to the Corporation for National and Community Service, which is releasing the report today. It showed Miami with a volunteerism rate of 14.5 percent, replacing Las Vegas in last place among major metropolitan areas.
Utah, at 43.9 percent, was followed by Nebraska, Minnesota, Alaska and Montana. Nevada had the lowest state rate, 17.7 percent; Florida and New York were the next lowest.
Provo had a 63 percent rate - the highest of any jurisdiction in the report - among 25 mid-size cities studied.
The high volunteer rates in Utah and several of its cities are attributed in part to civic-mindedness among the state's many Mormons, but Bill Hulterstrom, president of the Provo-based United Way of Utah County, said other factors also were at work.
''I believe that people here really feel like they can make a difference,'' he said. ''We do not wait for others to 'fix' our problems or neighborhoods.''
Rapid turnover is a problem across the country, and one of the reasons the national rate dropped again in 2007 after reaching 28.8 percent in 2005. In all, 60.8 million Americans 16 and older performed roughly 8.1 billion hours of volunteer service in 2007.
On the bright side, the report concluded that ''volunteer intensity'' is increasing, with 34 percent of volunteers contributing more than 100 hours of service in a year.
On the worrisome side were mounting concerns that economic woes - including high gasoline prices and job insecurity - would be deterrents for some would-be volunteers.
''With more people in need - losing houses, losing jobs - there are more people to serve,'' said CNCS board chairman Stephen Goldsmith. ''You have fewer people helping and more people needing help.''
By region, the Midwest had the highest volunteer rate at 31.1 percent, followed by the West at 26.1, the South with 24.7 and the Northeast at 23.4.
The CNCS, an independent federal agency, used Census Bureau data to determine its state and city rankings, which are based on three-year averages for 2005 through 2007.
In Florida, Harve Mogul, president and CEO of the United Way of Miami-Dade, said Miami's low ranking wasn't surprising because of the number of new immigrants.
''We have such a high number of recent immigrants who come from countries without the same organized philanthropy found in the United States,'' he said.
Still, Hands on Miami, which coordinates volunteer efforts for the local United Way, reported a marked increase in the number of volunteer hours: from 58,232 in its 2006-07 tally to 70,000 in 2007-08.
Lynn Heyman, who heads the volunteer program at Miami Children's Hospital, said she has 600 active volunteers at any given time, more than ever. But the hospital must hold orientations twice monthly to keep volunteers streaming in to replace departing ones.
Ani Olmeda Gonzalez at Mercy Hospital said the tough economy was forcing some would-be volunteers to choose paid work instead, and Cathy Agosti of VITAS Innovative Hospice Care noted what many others repeated.
''Busy lives,'' she said. ''Busy lives.''