Answers to this and other related questions can be found on (drum roll please)
www.washingtonlakes.com But for young smolts I'll print out the info here (BTW, there is also a lake contour map for Black Lake you can print out):
Black Lake (570 acres): This lake 4 miles southwest of Olympia is slow for 9- to 11-inch rainbows, better later in the summer for cutthroat, largemouth bass, perch and crappies, with a few brown bullheads available. There is a state access with boat launch and two toilets. Year-around fishing season. Disabled accessibility - Level 2. WCT, Blk Tpa, lgs.
From: Micro Brew
Public access is on the S.E. shore off of Black Lake - Bellmore Rd. S.W.. It is at Kennydell County Park.
Lake the Black Lake exit off of 101. At the bottom of the exit turn left, stay on main road until Black Lake - Belmore Rd. This road passes the north end of the lake.
From: Bob
Traveling south on I-5, just south of Olympia, take the Black Lake-Trosper Road exit. (Exit #102) Turn west onto Black Lake-Trosper Road for 2.8 miles to Black Lake-Belmore Road. Turn left (south) onto Black Lake-Belmore Road for 1.0 mile to 66th Ave. S.W.. Turn right onto 66th Ave. S.W. for .7 mile to the WDFW Public access area. The last time I was there the access had two good concrete plank boat launching ramps, lots of parking space for tow rigs and trailers and a couple of older pit toilets. Good luck and don't forget to release most of your fish unharmed. A nice bass is too fine a resource to enjoy catching only once. BJ