FATMAP difficulty grade
From Simkin Peak, head eastwards, and you will have a rocky area to your right, as the gradient begins to steepen.
From here you have a choice of two gullies (as shown on the map) with the northerly being generally steeper, with a steep section around the middle before dropping into a nicely gladed area, meanwhile the southerly gully maintains a slightly mellower gradient down to Leatherbarrel Creek commonly holding better snow conditions.
From the top, the two gullies are distinguished fairly easily, for the southerly gully, at the beginning you will have a rocky area to the right as you head eastwards off Simkin, follow the rocky line towards the south, and you will soon see the gully begin to form below you on the more shaded southerly face, the area below features some nicely spaced trees, before meeting the main drainage line to the south, keep to the left of the creek as it can often open up throughout the season.
For the northern gully, as you head eastwards off the peak, you will see a knoll in front of you on the way down, the gully then follows the drop off this, sometimes corniced, knoll.
After this knoll, the run steepens down to the tree line, from here follow the drainage lines down to Leatherbarrel Creek through the trees.
As stated above the knoll on the northerly gully can hold a cornice, so take care with it and avoid when warmer temperatures in spring hit, as it will be more prone to collapse.
Snow conditions here are generally pretty good, with the southern gully holding fresh snow and the base better than the northern gully, with the top section for both, often being scoured by the wind.
For the return, either head up the slope again, taking care of the cornice on the northern gully, I would say by keeping to the ridge line on the left on the way up to avoid them, or head up Golden Gully for a return to Dead Horse Gap.
If you're heading back to Thredbo, follow the Leatherbarrel Creek return, as shown on the map.