Parking is usually easily found but you must pay for the day fee or purchase an annual Coronado National Forest permit.
From the Roundup Picnic Area, start heading up Old Baldy Trail #372
for about 0.3 miles and then continue straight onto Vault Mine instead of taking the first switchback up Baldy. Initially, the trail is a little rocky and actually gets a bit smoother as it goes along, but also much steeper.
Once past the turn off for Baldy, continue approximately another 0.6 miles and look for the continuation of the Vault Mine Trail on your right hand side. Staying straight will lead you to the seldom used Carrie Nation Mine Trail. Once making this right turn, the pitch increases even more and the real fun elevation gain starts!
The trail itself past this point is very easy to follow. There are a number of switchbacks and some just downright steep sections to grind through. You'll pass an open cave on your right that you can't miss and eventually top out at the Agua Caliente Saddle, where Vault Mine intersects with Agua Caliente Trail #140
From here, you can head southeast on Agua Caliente towards Josephine Saddle and either continue up to Wrightson or head back down Baldy or Super Trail #134
. Vault Mine is definitely not a beginner trail due to its steepness, but it isn't terribly long either.
All the usual desert creatures found in southern Arizona, and a healthy supply of black bears reside in the area too.