The drive up to the Mahogany Flats campground (and trailhead) sometimes, depending on weather and current road quality, may require a high clearance vehicle, and possibly even 4WD. Check the DVNP website  http://www.nps.gov/deva/ " for "The Morning Report" for road details. Look for conditions on "Wildrose Road". If you don't have 4WD you can usually get as far as the Thorndike Campground. It's less than a mile up the road from Thorndike to the trailhead.  Once hiking, stay on the trail as there are many protected plant species that grow everywhere.