You can't really cut a ribbon to open a river to canoeists, so a coalition of groups promoting paddling up and down the Connecticut River did the next best thing Saturday - they held a picnic and a celebratory paddle from Gillette Castle State Park to Selden Island State Park in Lyme.

About 80 people attended the event, with about half of them taking to the river after lunch for the estimated one- to two-hour paddle down the river in perfect summer solstice weather.

The event marked the announcement by the Connecticut River Watershed Council, the Appalachian Mountain Club and the Vermont River Conservancy that the entire approximately 400 miles of the river was now included in the Connecticut River Trail.

"We're not really cutting a ribbon," Connecticut River Watershed Council Executive Director Andrew Fisk said at the start of the event. "But we're here to say finally, finally, finally, we're here to extend the trail to the sea."

The Connecticut River Paddlers' Trail has been well-established in New Hampshire and Vermont, with more than 30 primitive campsites for paddlers every five to 10 miles maintained by various volunteer groups.

The new plan, still a work in progress, will extend the trail the remaining approximately 200 miles into Massachusetts and Connecticut. A particular challenge is the 85-mile "gap" in campsites and dam portages in Massachusetts and northern Connecticut, said Noah Pollock of the Vermont River Conservancy.

Coalition members have been contacting private landowners and railroad companies along the river for easements to tiny parcels for primitive overnight campsites and are working with state agencies for more official campsites. Pollock said campsites can be as small as 200 square feet to accommodate single or small groups of paddlers.

Advocates also promise to work with paddlers to ensure that campsites are cleaned up with the "leave no trace" goal.

There are 15 hydropower stations along the northern portion of the Connecticut River, with some portage paths better than others, Pollock said.

"Some are a mile long and involve a walk through town," he said.

People have been paddling the Connecticut River for centuries to catch fish and for easy transportation. More recently, those who execute their dream to paddle the entire length of the river are called "through paddlers" - akin to the "through hikers" term for the Appalachian Trail.

Perhaps the most famous through paddler in recent decades is Hartford Courant columnist Steve Grant, who chronicled his journey for the newspaper in 1991. Grant was a guest speaker Saturday and announced that he was "thrilled" at the extension of the Connecticut River Trail.

Grant told stories of facing long portages weighed down with too much gear, begging for rides to the other side of a dam. Some nights, he camped beside "no camping" signs at boat launches.

He reached the trash-strewn banks in Springfield one June evening having no idea where he would pitch his tent. That's when "trail magic" rescued him, he said. A pontoon boat approached with four people who had heard his story and invited him not only to camp on their spacious riverfront lawn, but to join them in a barbecue feast prepared by these professional caterers on their day off.

Kristen Sykes, director of conservation strategies for the Appalachian Mountain Club, announced Saturday that two new official campsites in Massachusetts should open by this fall or next spring.

"This is so terrific," Grant said. "This trail map, campsites. In 1991, there were not a lot of organized campsites."

In Connecticut, the state Department of Energy and Environmental Protection is working with Connecticut River Trail organizers to publicize available public campsites along the river, such as state park campgrounds, DEEP spokesman Dennis Schain said.

"DEEP is in total support of the Connecticut River Trail concept. It is a tremendous and smart way to highlight all that the Connecticut River and surrounding areas have to offer and showcase what a great resource the river is," Schain said.

c.bessette@theday.com