Old Man's, along with Old Lady's, are the two easiest and most popular routes at Seneca. Old Man's traverses the majority of the west face of the south peak and crosses many other popular lines. On a crowded weekend, it will take you all day to wait in lines and wait for the way to clear. Nevertheless, it is a classic route frought with history and steeped in lore. It is a decent lead for a beginning climber.
Approach via the west-side climber's trail: cross the bridge from the parking lot and turn right at the sign. Head up Roy Gap Road to the gap and cross the creek on large boulders. Head up the famous "Stairmaster" to the west face. Hike north along the face to the large starting platform.
The route starts toward the north (left) end of the west face, south peak very near the huge, north-facing Thais dihedral. The popular routes Conn's West/Direct (5.4) and West Pole (5.7) share the same starting pitch, so it is often crowded on a summer weekend.
P1: start up low-angle bulges to an obvious left-facing corner with a tree.
P2: keep heading up and right on alternating ledges and steep, short corners to a second belay alcove.
P3: traverse right (3rd class but exposed) around a bulge to the top of Front C (5.5) where a firstaid cache (metal box) is bolted to a tree. This is another busy area at the top of several other popular climbs (Front C, Le Gourmet) and directly below the aptly named Traffic Jam rappell.
P4: when the traffic has cleared, climb up easy terrain to a steep wall (crux) directly under the Traffic Jam chimney. Thread the chimney and emerge on the summit ledge.
Some parties run the first two pitches together. Beware, however, that you will be out of sight and possibly out of hearing of your belayer and rope drag may be a problem.
Descent: There are two popular rappel stations on the west face. Three single-50-meter rope descents from Traffic Jam will bring you to the ground. With double 50s, you can combine the lower two nicely. On the north side of the summit ledge, the West Pole rappell is also popular requiring three single-rope raps or a double followed by a single.
Bring a 50 meter rope and a trad rack. Rock conditions vary conciderably from pitch to pitch and all sorts of gear can be used. Bring slings for trees and horns, medium sized stoppers and hexes, and an assortment of cams. Double ropes will make the descent easier, but at least two rappels will be neccessary in any case.