Standing on the banks of the River Derwent, Jeffry Bog is a relic wet pasture with an important lowland marsh that is embraced by the Howardian Hills Area of Outstanding Natural Beauty.

Despite its small size, the range of different habitats make this an interesting place to visit, particularly during the spring and summer. In spring the grasslands are yellow with the flowers of cowslip and primrose, whilst in the wetter areas the large glossy heads of marsh marigolds can be seen. Other notable plants early in the season include early purple orchid. Adjacent to the nature reserve, areas of wet woodland known as alder carr will be coming into leaf.

By summer the cocoons of spiders and moths can be found among the tall grasses. The grasslands thrive with betony, great and salad burnet, and common spotted orchid. In the marsh, blunt-floweered rush, oval and brown sedges, and marsh arrowgrass can be found among the cream sprays of meadowsweet, cerise ragged robin and prominent yellow flag iris. At ground, level, some spiders can be seen carrying parcels of young whilst others guard territories. Damselflies and day-flying moths can be seen in abundance on warm, sunny days.

Keep an eye overhead as buzzards are a regular sight. Look along the riverbank as signs of otter presence are frequent, though this shy mammal is only rarely seen. Barn owls can be seen at any time of the year hunting for voles, though are most active when feeding young in summer. Kingfishers are a regular sight along the river, joined in summer by an occasional common tern and in winter by goosanders. There is historical evidence of farming on site, with remnants of ridge and furrow to be seen in the grassland. Today, Yorkshire Wildlife Trust grazes the nature reserve with cattle to help encourage wildflowers.

• Spring: Plants - Early purple orchid; Cowslip; Primrose; Marsh marigold
• Summer: Plants - Marsh valerian; Betony; Invertebrates - Banded demoiselle; Yellow meadow ant
• Autumn: Birds - Buzzard
• Winter: Birds - Goosander; Barn owl

Public transport
Malton buses stop in Westow.

By car
Six miles south west of Malton, two miles east of Kirkham Abbey and about one mile north of Westow. Park cars at the roadside opposite the entrance to church farm being careful not to obstruct either of the farm tracks. Walk down the farm track opposite the farm to the nature reserve. The Centenary Way footpath along the river passes through the site.