We hiked up SL from Caribou Pond Rd last weekend here is the report:
the road itself is in good shape. the culverts are in very bad shape. some hardy Subaru made it to the trail head parking, but one had to park short and walk in. SUV or truck is certainly preferable. several of the small diameter CMP and HPDE culverts are 80% exposed and you have to drive over them. other crossings have significant washouts with deep ruts. probably 5 or so dicey crossings that you will want big tires or high clearance for.
wildflowers are starting to really pop on Caribou Pond road past the gate.
AT has clearly had some trail maintenance in this section. a brand new AT sign at the road crossing. the campsite and water crossing at the south branch were both in fine shape. stone stairs all looking good.
further up above the scramble section a few places were totally rebuilt with scree stone and small boulders. looking good and trail starting to dry out nicely. some small erosion problem areas remain in lower forested section and the highest forested section before junction with Spaulding trail.
GREAT water source on SL summit spur trail. flowing strong and box newly maintained with tight fitting lid. no bugs, good clarity.