Having just purchased our first canoe, decided to use Mountain Run Lake for our maiden voyage, it…read morebeing a mere 15 minutes or so from home. While we've visited this county park a few times just to walk around, this was our first experience on the lake itself, thus my comments are pretty much just based on our lake experience.
The park itself, apart from the lake, has quite a bit of property & amenities for a nice day outdoors. Lots of green open space, some walking trails (which we have yet to investigate), & a fair number of covered picnic shelters with grills &/or very nice brick fireplaces. As far as boating facilities, there is one very small wooden pier & an equally small concrete boat ramp. Since we were "launching" a canoe, was glad I was wearing my new little breathable "quick dry" water shoes, since it was impossible not to get wet during the process.
Mountain Run Lake is considerably smaller than Culpeper's other lake property - Lake Pelham, which runs a canoe/kayak/paddleboard/paddleboat etc. concession - Mountain Run being a mere 75 acres to Lake Pelham's 225. Thus, it took us only about an hour to do Mountain Run's entire perimeter, & that was just via slow, leisurely paddling. (In comparison, we usually spend around 3 hours on Lake Pelham, including a 1/2-hour or so on-water lunch break.)
Since we were there around 10:30 a.m. on Labor Day, there were LOTS of people fishing - both along the banks & from boats. It never ceases to amaze me that no matter how many times we visit a local waterway & see people fishing, we've yet to see anyone ever catch anything - lol! Regardless, we did our best to be considerate & stay as far away from fishing people as we could. (Unfortunately, we did just barely miss mowing down some poor guy's line, but to be honest, he was standing completely hidden in the brush on the banks, right around a corner, & there was really no way for us to know he was there. We apologized profusely, but just got a glare. Oh well.)
Being an avid birder/naturalist, I was of course more interested in the wildlife than anything else. Quite a bit of deep purple Ironweed & a few patches of brilliant red Cardinal Flower blooming on the banks. Saw lots of Painted Turtles; a beautiful Great Egret; several Great Blue Herons; one very small heron that was either a Little Blue or a Little Green; Canada Geese, along with one big visiting domestic-looking Greylag goose; a handful of hybrid ducks; & the piece de resistance - an OSPREY!!!! It flew right by our canoe, carrying a fish. I had no idea that we had Osprey in Culpeper, but it was close enough to be absolutely unmistakable.
Weather was absolutely lovely, & all in all it was a very nice, if short, trip.
Bottom line - nice, clean park. Only caveats are that 1) being so nice & clean, it's extremely popular on weekends & holidays, so if you're looking for solitude you need to visit early in the day; & 2) Parking is extremely limited. Like most county parks, park is open from dawn till dusk.