Be aware that the official SLT is closed near the Cathedral Rock Parking. Drive a bit up the road for Mary Jane Falls and Trail Canyon, and take the first road on the left (before Mary Jane turn-off). Park there and head SE to the SLT trail It's a pain, but avoids a $275 ticket). Or just go up the NLT from Trail Canyon.
update: Seems now it is open by Cathedral Rock, but not at the regular trailhead. Ascend the steps and cut left on a connecting trail.