I made up the name Snoopy's Sister as Snoopy's Backside is an unofficial name, too.
On this picture Snoopy's Sister is the tiny snow coulouir to the left; right below the summit walls of The East Citadel.
The wide snow interstate of Snoopy's Backside Chute is to the right.
Snoopy's Sister can only be seen from the Gulch beneath the Citadel's NE face. One can see only half of the coulouir from this point as the colouir is making a 90 degree turn to the left halfway up.
It is narrower, steeper and more prone to rockfall than Snoopy's Backside and thus a more challenging alternative to the upper part of Snoopy's Backside Gulch..
The obscureness of The Citadel, despite its closeness to Denver, ensures to have the whole mountain most likely for oneself
Start at Herman's Gulch Trail or hike up Dry Gulch and climb over the Dry/Herman saddle
Approach is identical to Snoopy's Backside Chute. Follow the Herman Gulch trail for approximately 3 miles. After the initial switchbacks up from the interstate, the paths levels out for a longer while (with shorter ups and downs in between).
After crossing two side creeks, one right after the other(the first one on two long wooden boards)the path becomes considerably steeper. Leave the path from here to your left and start bushwacking in direction of the rockface of The Citadel. Several faint animal and climber trails are heading in this direction; scrubb is not too dense.
Continue upward to the very top of the Gulch beneath the Citadel's NE face.
The wide coulouir right in front of you is Snoopy's Backside Chute. Climb up the chute until you reach its almost level midpart.Looking upward you will see another smaller snow chute to the left of Snoopy's Backside Chute right below the walls of East Citadel. Getting into the chute requires a short climb of several feet (might be less in spring with more snow).
Climb up the chute (around 45 degree), in its lower level you might hit one icy spot resulting from meltwater. Halfway up, the chute is taking a 90 degree turn to the left. The chute is topping out close to the East Citadel summit. No cornice in July, what doesn't mean there isn't one in spring.Turn to your right and you will be within a couple minutes on the summit.
Crampons,ice axe and helmet. Chute is narrow;lots of loose rock right above your head and plenty of mountain goats who happily let this stuff rain down on you