The umbrella organization will retain its name, Boy Scouts of America. The term Cub Scouts, for kids 7-10 years old, is gender neutral and also will go unchanged. Boy Scouts, which runs through age 17, will become Scouts BSA in February.

"As we enter a new era for our organization, it is important that all youth can see themselves in Scouting in every way possible," Saurbaugh said.

Chief Scout Executive Mike Surbaugh also unveiled the group's new "Scout Me In" marketing campaign aimed at promoting inclusiveness.

The Boy Scouts of America doubled down Wednesday on their quest to become the scouting program of choice for boys and girls, announcing they will drop "Boy" from the name of their signature program.

Cub Scouts will formally accept girls starting this summer. But Saurbaugh said more than 3,000 girls nationwide already enrolled in the BSA's Early Adopter Program and are participating in Cub Scouts ahead of the full launch.

"Cub Scouts is a lot of fun, and now it's available to all kids," said Stephen Medlicott, marketing director for Boy Scouts of America. "That's why we love 'Scout Me In' – because it speaks to girls and boys and tells them, 'This is for you. We want you to join!'"

Boy Scouts of America claims almost 2.3 million members, down from 2.6 million five years ago. That includes Venturing and Sea Scouting programs, the latter allows membership up to 21 years of age. In its peak years, Boy Scout of America had more than 4 million participants.

Adults play a major role in the program, with almost 1 million adult volunteers serving as the backbone of the organization.

Surbaugh predicted that both boys and girls in Scouts BSA would refer to themselves simply as scouts, rather than adding "boy" or "girl" as a modifier.

The program for the older boys and girls will largely be divided along gender-lines, with single-sex units pursuing the same types of activities, earning the same array of merit badges and potentially having the same pathway to the coveted Eagle Scout award.

Surbaugh said that having separate units for boys and girls should alleviate concerns that girls joining the BSA for the first time might be at a disadvantage in seeking leadership opportunities.

Girl Scout leaders said they were blindsided by the move, and they are gearing up an aggressive campaign to recruit and retain girls as members. Girl Scouts, founded two years after Boy Scouts, currently claim a membership of about 1.8 million.

Among the initiatives is creation of numerous new badges that girls can earn, focusing on outdoor activities and on science, engineering, technology and math. The organization is expanding corporate partnerships in both those areas, and developing a Girl Scout Network Page on LinkedIn to support career advancement for former Girl Scouts.

The overall impact of the BSA's policy change on Girl Scouts membership won't be known any time soon. But one regional leader, Fiona Cummings of Girl Scouts of Northern Illinois, believes the BSA's decision to admit girls is among the factors that have shrunk her council's youth membership by more than 500 girls so far this year.

She said relations with the Boy Scouts in her region used to be collaborative and now are "very chilly."

"How do you manage these strategic tensions?" she asked. "We both need to increase our membership numbers."