More than 150,000 visitors are expected in Thurmont this weekend for the 42nd annual Catoctin Colorfest, during which more than 360 juried arts and crafts vendors will exhibit their wares throughout town in three areas within walking distance of each other.

The craft areas are at Thurmont Community Park and Guardian Hose Company Activities Grounds and in front of the Thurmont Middle School. They will be open from 9 a.m. to 5 p.m., Saturday and Sunday. Admission to all the craft areas is free. Food will be available, and many people will also hold yard sales throughout the town.

A postal envelope commemorating the event, designed by Colorfest Committee Vice President Carol Robertson, will be available for the first time this year at the U.S. Postal Service’s mobile unit, set up in the park. Colorfest postcards will also be available at the mobile unit, where people can stamp mail with a cancellation celebrating the 42nd Annual Colorfest.

‘‘There has been something new and different every year," Colorfest President Beverly Zienda said.

Zienda has been president for 26 years, but has been involved with the event for 31 years. The past week has been hectic for Zienda and the rest of the committee, as they set up spaces for the craft booths, and got everything in place for the exhibitors to come in on Friday.

Catoctin Colorfest was recognized in the top 35 arts and craft shows in the U.S. by Sunshine Artists Magazine this year, but started out as a simple celebration of nature.

Colorfest has been a tradition in the town since 1963, when Catoctin Mountain Park naturalist Duncan Burchard organized nature walks through the area, attracting 60 people each year, according to the Catoctin Colorfest Web site. The event expanded to include art exhibits, church dinners, orchard tours and apple butter boiling, and by 1971, 30,000 people participated.

Volunteers working under the direction of the Catoctin Mountain Tourist Council started inviting craftspeople to participate in 1973, and the event has expanded yearly since then. The exhibitors come from all over the United States, some from as far away as California.

‘‘In the course of the year we might get 1,000 applications, but we only accept 350," Robertson said.

The first Colorfest committee was formed in 1974 to plan for the next year, since the event had already started attracting large crowds, and nearly 75,000 people came in 1975. In 1977, then-Colorfest President Ernest Hall instituted the first annual Catoctin Colorfest dinner meeting, held in November of each year. The committee distributed 30,000 brochures that year to advertise the event, and held a raffle with craft prizes donated by participants to cover the printing costs.

By the time the Colorfest reached its 20th year in 1983, the event had become so successful that the Colorfest committee actually had money left over to donate to the town and to establish a scholarship at Catoctin High School.

Each year following that, the Colorfest committee put their proceeds from the event back into the community.

Over the years, the Colorfest committee has paid for improvements to the town’s parks, given annual donations to Thurmont’s local schools and added an annual scholarship program to include an award for local adults returning to college. The Colorfest committee also supports the town historical society, and has purchased new Christmas decorations for the town.