National trail can be acended or decended. Both require expert skills and fitness. You cannot and will not find a climb this technical, challenging and fun in AZ. It will kick your ass and youll love every turn of the peddle. You can ride this trail 365 but, beware of mid afternoon temps in the summer, "theres birds that will pick your bones clean."
1-10 to Baseline Road go right (west) to 48th street. Take 48th street 1/4 mile past Euclid and turn right (sign indicating park entrance). Go 400 feet and turn left head to parking lot/trailhead.
http://www.singletracks.com/item.php?c=1&i=810