Glenummera Valley | Mayo

Overview

Glenummera Valley (Irish: Gleann Iomaire) sits in the barony of Murrisk, County Mayo, on the western edge of the Sheeffry Hills. The Irish name translates roughly to “valley of the ridge”, a fitting description for a U-shaped hollow hemmed in by sharp, glacially sculpted ridgelines. Running east-west between the Sheeffry range to the north and the prominent peaks of Ben Gorm and Ben Creggan to the south, the valley floor is characteristically boggy and crossed by a meandering stream. There has never been a permanent settlement here; instead, the area has long functioned as a natural corridor for shepherds and, more recently, as the most accessible starting point for serious hill-walkers in the region.

Getting There & Parking

The valley is reached via the R335 road, a short detour west of the village of Leenaun. A small lay-by on the roadside serves as the only parking area and fits roughly one vehicle. During peak summer months, arrive early to avoid circling for space. If you are travelling without a car, Leenaun is served by Bus Éireann routes from Westport and Ballina, though services run infrequently outside the summer season. Always check current timetables before relying on public transport.

Recommended Routes

Glenummera Valley is primarily valued as a trailhead. The surrounding peaks offer rewarding but demanding terrain, best suited to hikers with experience in mountain navigation and variable weather.

Ben Gorm & Ben Creggan – The most popular objective. The out-and-back route covers approximately 8.15 km with an elevation gain of 686 m, taking 4.5–6 hours. The initial ascent is steep and boggy, transitioning to a rocky ridge. The final 200 m to each summit lacks a defined path and requires careful footwork over loose stone. From Ben Creggan’s summit cairn, a short step down frames the classic vista of Doolough Valley, with the sheer cliffs of Ben Lugmore and the distant profile of Mweelrea.
Barrclashcame & Tievummera – A longer, high-altitude ridge walk linking two Sheeffry peaks. The out-and-back distance is roughly 12 km with 800 m of ascent, taking 5–6 hours. The approach from Glenummera is less steep than the Doolough side, making it a preferred alternative for those wanting to avoid the initial vertical climb. The ridge is exposed and features occasional open fault lines that demand caution in poor visibility.
Alternative via Aasleagh Falls – Starting from Aasleagh Falls, this route covers about 11 km with 832 m of elevation gain. It adds a scenic waterfall detour but increases the total distance and time commitment.

There are no way-marked trails in Glenummera Valley. A detailed Ordnance Survey Ireland 1:25 000 map, a reliable GPS device, and a compass are essential. Ridge paths can disappear quickly in low cloud, and the terrain shifts rapidly from peat to loose rock. Mobile reception is limited across the valley floor and ridges, so always inform someone of your planned route and expected return time. The open fault lines on the higher ridges are a genuine hazard; avoid them in wet or snowy conditions when the edges become unstable.

Wildlife & Landscape

The valley’s mix of blanket bog, heathland, and rocky outcrops supports a range of upland species. Walkers frequently spot red deer and hares moving through the lower slopes, while golden eagles are known to soar above the ridges. Late summer brings colour to the landscape as heather and bilberry bloom, attracting butterflies such as the silver-studded blue. The valley’s streams are home to brown trout, though fishing is restricted to licensed areas and should be approached with care to protect sensitive habitats.

Nearby Stops & Accommodation

Glenummera Valley sits within a short drive of several useful staging points:

Aasleagh Falls – A dramatic cascade on the River Erriff, easily accessible via a short side-track from the alternative Ben Gorm route.
Sheeffry Pass – A scenic mountain pass that can be driven from the Westport side, offering dramatic photo opportunities before you even begin hiking.
Leenaun & Westport – Both villages provide a range of guesthouses, B&Bs, and pubs. Westport, on the edge of Clew Bay, is the largest nearby town with comprehensive dining and accommodation options.

Practical Information

Entry & Facilities: The valley is free to access and open year-round. There are no visitor centres, toilets, or cafés on site.
Water: A small pond sits on the ridge near Ben Creggan’s summit. Water should be boiled or filtered before drinking. No other reliable sources exist on the main routes.
Seasonality: May, June, and September typically offer the driest footing and longest daylight hours. The valley is accessible in winter, but boggy sections can freeze and snow may conceal fault lines. Winter visits require mountain boots, gaiters, and experience in cold-weather navigation.
Dogs: Dogs are welcome on all trails but should be kept under close control. A lead is strongly recommended in winter when the ground is icy, and always keep them away from sensitive bog areas and livestock.
Preparation: Pack layers, waterproofs, and high-energy snacks. Weather in the Mayo uplands changes rapidly, and temperatures drop significantly on the exposed ridges. Start early to allow plenty of daylight for descent, and check the Met Éireann forecast before heading out.