But that's a big drop from the 125,000 estimated GOP caucus-goers in 2012.
"2012 was a unique year, so it's hard to compare," Evans said.
That year, Sen. Orrin Hatch spent millions to attract attendance, worried that small crowds might allow the tea party to wield power beyond its numbers and dump him. The tea party in 2010 did eliminate Sen. Bob Bennett, even though polls at the time showed the three-term Republican likely easily would have won a primary.
Also, 2012 was a presidential election year, and adopted favorite-son Mitt Romney was running. The LDS Church that year did an unprecedented heavy push for caucus attendance, canceling meetings that interfered and reading letters from the pulpit for weeks urging participation. It repeated that effort this year.
Given the high-interest races in that election, party leaders aren't surprised at the smaller numbers this time.
"A presidential year is always a year with higher turnout and participation. So the lower turnout this year was to be expected," Lyon said.
Even though attendance is down from two years ago, both parties say the overall tide of attendance has risen perhaps because of concerns raised by the Count My Vote initiative that sought to replace the caucus-convention system with a direct primary.
"I think some of that drilled our turnout, where people said, 'Let me see for myself what is going on here,'" Evans said.
Attendees at caucuses elected about 4,000 GOP delegates and 2,600 Democratic delegates to state conventions. If candidates receive 60 percent of delegate votes there, they proceed to the final election. Otherwise, the top two vote-getters run in a primary election.
Under SB54 that Gov. Gary Herbert just signed into law, the system will change for the 2016 election under a compromise with Count My Vote organizers. It will allow the caucus-convention system to continue, but give candidates a way to bypass it and appear in a primary by gathering enough signatures.
Evans said that after his party's April 26 state convention, it will consider whether to challenge SB54 in court as a possible unconstitutional interference with how it chooses its nominees.
Generally rising attendance belies assertions by critics, Evans said, that caucuses are not representative of the general population, and tend to favor extremists who can pack small-attendance meetings with friends.
"I think this attendance disputes that," Evans said. "I think caucuses are the most representative form" of choosing candidates because neighbors get together to discuss what they want from the party and its nominees.
Both parties said they found many people who attended caucuses for the first time ever this year perhaps from the Count My Vote controversy and efforts by the LDS Church to push attendance.
Evans said that has prompted his party to consider a year-round educational effort to "ensure new caucus attendees can now connect the dots around the year" about how their attendance affects elections and politics.
He said the party also streamlined meetings to keep them under two hours, to help encourage people to return. He said most of that came by offering preregistration on line, to shorten lines at meetings. About 30,000 Republicans pre-registered.