My active outdoorsy D23 committed to a summer long music festival that starts on June 19th, but is looking for a short teen expedition program in the first two weeks of June. Majority of the programs we came across start in July or later.
She is interested in sea kayaking, or kayaking in general, or a mixed backpacking/kayaking/whitewater program. Couple of years ago she did a week long San Juan Islands kayaking expedition in WA and had a blast.
In addition to NOLS, Outward Bound or Overland Summers might have something in that vein. Might be worth looking to see what High Mountain Institute offers in terms of summer sessions.
Sometimes the rivers are too cold or too fast because of spring run off until later in the summer. I think many tour companies have had to cancel or postpone too many times to schedule them.
I think school calendars play a role too. Kids start school first week of August, and are out of school around May 25th here, in GA, noticed it is different in Northeast or Northwest. More of September to June cycle. Thank you!