This gps track takes you up both of the service roads in HTMP.

http://trail.motionbased.com/trail/invitation/email/accept.mb?senderPk.p...

Park (or ride to ) the soderburg parking lot ($6 daily parking or $65 annual). Start riding and take the road back out to the main hwy then head up to the HTMP lot at the top of the hill. Water and bathrooms here. Take the service road up towards the top. At the 4 way intersection head left up the steep and rocky scree field. Another 100 yards later there is turn off on the right for Wathan trail. Take this down. Almost immdediatly you hit a turn for westridge on the left and up, and wathan on the right. Go right down wathanon the right. Follow this down for a ways. At the bottom of wathan there is a turn for spring creek. Take this up and to the left. A little ways up there is a uphill turn on the right, Herrington. Take this. At the top of Herrington, turn right. This will put you on stout. This winds around for a while and eventually puts you on the service road for the towers. Take a left here and head up. About three miles up there is a turn on the right for Mill Creek. Take this down and enjoy. Nice and technical. Rock, waterbar, rock, switchback, repeat X20. Enter Lory State Park. Towards the bottom there is a left hand turn for Howard. This is optional. Otherwise keep going straight till you in the main vally of either Aurthors rock or Nomad. Take this right. You will pass the towers service road again. Find the trail that heads down to the soderburg lot and your car.