While the state park is pretty, a less expensive alternative is Wenatchee River County Park. The last time I checked the prices for the state park they were pretty steep for a non resident.
Trailer: 2013 Escape 21 Classic Number 6, pulled by 2018 Toyota Highlander
Posts: 8,259
Coming from the west just before you get to Leavenworth there are a series of US Forest Service campgrounds on Icicle Creek. As you drive through Leavenworth there is a Forest Supervisors Office. If they are closed there are usually brochures in a box outside with a rock on them. If they are open you can go inside and get lots of information including the newsprint Forest service paper that has maps and points of interest around the area. Leavenworth is very popular and the advice to get reservations any time after about May 15’to after Labor Day is good advice. We were there in 2017 on a Sunday. There was a music program in town with oom pah bands and those 12 foot long horns. Did not See anyone hawking cough drops though. Lots of lederhosen.
Iowa Dave
Leavenworth is part of the Cascade Loop, a 3-4 day adventure that traverses 9 different geographical regions with lots to see for every one. If you have the time, you may want to check it out: https://www.cascadeloop.com
Our favourite spots included the North Cascade mountains, Lake Chelan, Winthrop, Leavenworth and Whidbey Island.