When do you plan to fish in (or near) Shenandoah county? During the winter/early spring months, your best bet will be stocker streams - Stony Creek or Passage. It's stocked fishing at it's finest and you'll see the many access points with pull offs on the side of the road. Both were recently stocked, however the water's low and the put and take crowd gets there quickly but with some effort/exploration you can find fish. With precipitation moving in over the next few days this may allow what's left of the recent stockers to move around some. Fall fish, blue gill and an elusive smallie have been caught in both streams too.
I think your best bet would be to use your proximity to the South River in Waynesboro or Mossy Creek outside of Harrisonburg and focus in that general area (lots of options). The winter trout fishing gets exponentially better around those two cities. Harry Murray is a good resource, Mossy Creek fly shop in Harrisonburg and South River Fly Shop in Waynesboro are both fantastic operations owned by good people.
The upper reaches of the North Fork Shenandoah are stocked this time of year as well, and their tributaries. They do not stock the North Fork Shenandoah in Shenandoah County (I wish they would...) that part of the river is a warm water fishery that has unfortunately been severely negatively impacted from the high water events of a few years ago. I'm hoping it will rebound, only time will tell. Exciting to hear about the muskie sighting!
Feel free to reach out directly with questions, my folks retired out there so I spend a good amount of time fishing all over the valley. Also, stop into the Woodstock café both for supplies (fantastic retail wine/beer options) and amazing breakfast/lunch and weekend dinner (or safe carryout option). Chef Jose is absolutely crushing it - truly a valley treasure (not affiliated just a huge fan of them).