Summertime brings familiar sights to the Yakima Valley — rafts on the Yakima River, fruit-laden trees and recreational vehicles all over the place.

In June, members of Sisters on the Fly, an international women’s organization with a focus on the outdoors, brought their travel trailers to the Central Washington Agricultural Museum in Union Gap. Last weekend, Chinook RV owners gathered at Running Springs Ranch in Naches, the home of Chinook RV doyen Gary Lukehart, for their first rally there since 2003.

And in less than two weeks, about 50 vintage trailers are expected at the annual Nile Valley Rally at Jim Sprick Park on State Route 410. The rally open house is set for 9 a.m. to noon Aug. 17 at the park at 13680 Highway 410 outside Naches. It’s a free event and quite popular; expect a crowd. It ends promptly at noon.

Among the restored vintage camp trailers will be a 1948 Curtis Wright Trailer owned by Dave and Lori White of Walla Walla. It received Best of Show at the Pismo Beach Trailer Rally in California earlier this year.

Vintage trailers abounded when members of Sisters on the Fly met in June for their 14th annual Northwest Gathering at the Central Washington Agricultural Museum in Union Gap. Robin Maillet of McKenna hosted the members-only event along with Jane Gutting of Yakima, Lynn Ahlers of Cle Elum and Nancy Baum of Soap Lake.

Until 10 years ago, the organization had a few hundred members. After it was featured on an HGTV show, the “Today Show” and Oprah magazine, membership increased by more than 250 percent in the past 10 years. It’s now more than 14,000.

Each member has a number. This particular gathering included member No. 2, Becky Clarke of Boise, Idaho. She and her sister started the group. Learn more at www.sistersonthefly.com.

The organization’s mission statement in part says it is “Offering empowerment and sisterhood through exceptional outdoor adventures.” In addition, members’ credo is, “We have more fun than anyone.” Members are encouraged to learn to fish, ride a horse, kayak, camp under the stars and travel to various destinations near and far.

Its rules are simple — “No men, no kids, be nice, have fun.”

Trailers at the gathering ranged from vintage to modern, most decked out with welcoming sitting areas and carefully coordinated décor. The amount of work that has gone into these trailers is phenomenal. And everyone helps each other.

Members drive their trucks and trailers themselves. Maillet explained that the group provides driving classes — Trailer Safety 101. They all help each other park and set up as necessary. Then it’s time to have fun.

“We are women on the road and girls in the campground,” Maillet said.

One of the main purposes of the group’s gatherings is to raise money for a local charity, chosen by the group, in the town where each event is held. Members do this by holding an auction among themselves. They bring items for the live and silent auctions. This year members raised more than $30,000 for Yakima Valley Pet Rescue, along with a generous donation to the Central WA Ag Museum.

Just like the Nile Valley Rally, the group sets a theme or themes for each gathering. This year’s themes included Overalls & Pearls, Farm Fillies and Frilly Hat Day (largely based on the venue of the Ag Museum), and members dressed to match the theme. Evening activities included a “Trailer Trash Prom.”

During the day members spread out through town shopping, dining, wine tasting and generally enjoying themselves.

“These ladies were a riot. They came in groups bringing laughter and joy, asking about must-see stops in town. We had a great time while they shopped,” said Tricia Ewing, owner of Gap Treasures.

Naches rally

During the Chinook RV rally last weekend, members had a barbecue and other fun gatherings at Gary and Mary Lukehart’s 150-acre ranch in Naches. The organization has two chapters, east and west, with the Mississippi River serving as the dividing line. The Chinook West chapter has had rallies as far north as Victoria, B.C. and as far east as Branson, Mo.

Members of the west chapter first gathered at Running Springs Ranch in 2003. Jim Wedemeyer of St. Joseph, Mo., was there then, as demonstrated by his well-kept commemorative T-shirt. He wasn’t going to let distance stop him this time, either.

“We drove 1,754 miles to be with our friends,” he said. “We enjoy the group.”

EDITOR’S NOTE: Jeanene Sutton, who oversees social media for Union Gap Tourism, contributed to this story.

Reach Tammy Ayer at tayer@yakimaherald.com or on Facebook.