Skyline, Long Ridge, and Windy Hill Open Space Preserves

San Mateo County Coastal Range

Skyline, Long Ridge, and Windy Hill Open Space Preserves occupy prime habitat in the coastal range of the San Francisco Peninsula. Habitats include dry chaparral, Douglas Fir, open grasslands, and Oak forest. Special butterflies include the scarce Unsilvered Fritillary, "Grinnell's" Pacuvius Duskywing, Coronis Fritillary, Bramble Hairstreak, "Chalcedon" Variable Checkerspot, and Golden Hairstreak.

Getting There

From Highway 280, take Woodside Road (Highway 84) west to its top at Skyline Boulevard (Highway 35). Turn left (south) and continue about 7 miles to the entrance to Skyline Open Space Preserve on your right. The entrance to Long Ridge OSP is a further two miles south. Windy Hill OSP is just a few miles south of the intersection of Highway 35 and Highway 84.

When to Go

The preserves can be visited with some success anytime from April to August.

Other Wildlife

Skyline OSP is a first-rate locality for dragonflies and damselflies. Birds include Lazuli Bunting, Ash-throated Flycatcher, Wrentit, Black-throated Gray Warbler, and (rarely) Pileated Woodpecker. Lawrence's Goldfinch is regular some years at Windy Hill OSP. Mountain Lions are present but rarely seen.

Species List

Abundance and months are conservative, restricted to confirmed records from these preserves.

Swallowtails

Anise Swallowtail (Papilio zelicaon): Common — 4–5, 7, 9
Western Tiger Swallowtail (Papilio rutulus): Uncommon — 3, 6–7
Pale Swallowtail (Papilio eurymedon): Uncommon — 5–7

Whites and Sulphurs

Cabbage White (Pieris rapae): Uncommon — 6, 10
Margined [Mustard] White (Pieris [napi] marginalis): Common — 3; Rare 6
Checkered White (Pontia protodice): Uncommon — 7
Large Marble (Euchloe ausonides): Uncommon — 3
Sara Orangetip (Anthocharis sara): Common — 4–5
Orange Sulphur (Colias eurytheme): Uncommon — 10

Coppers, Hairstreaks, and Blues

Tailed Copper (Lycaena arota): Uncommon — 6–7
Great Copper (Lycaena xanthoides): Rare — 6
Gorgon Copper (Lycaena gorgon): Uncommon — 5–6
Golden Hairstreak (Habrodais grunus): Abundant — 6–9
California Hairstreak (Satyrium californica): Uncommon — 5
Hedgerow Hairstreak (Satyrium saepium): Uncommon — 6
Brown Elfin (Callophrys [Incisalia] augustinus): Uncommon — 4–5
Bramble Hairstreak (Callophrys [dumetorum] perplexa): Uncommon — 4–5
Echo [Spring] Azure (Celastrina [ladon] echo): Common — 3–6
"Pardalis" Boisduval's Blue (Plebejus icarioides pardalis): Common — 5
Acmon Blue (Plebejus acmon): Common — 3–4; Abundant 5–9, 11
Silvery Blue (Glaucopsyche lygdamus): Uncommon — 4

Brushfoots

Coronis Fritillary (Speyeria coronis): Common — 5–9
Unsilvered Fritillary (Speyeria adiaste adiaste): Uncommon — 7–8 (Long Ridge only)
Pacific Fritillary (Boloria epithore epithore): Uncommon — 6
Leanira Checkerspot (Thessalia leanira): Uncommon — 5
Northern Checkerspot (Chlosyne palla): Uncommon — 5–6
"Chalcedon" Variable Checkerspot (Euphydryas chalcedona): Abundant — 5–7
Field Crescent (Phyciodes pulchella): Uncommon — 5
Mylitta Crescent (Phyciodes mylitta): Common — 4–8, 11
Satyr Comma (Polygonia satyrus): Uncommon — 5–6, 10
California Tortoiseshell (Nymphalis californica): Uncommon — 1, 4
Painted Lady (Vanessa cardui): Common — 5, 9–10
American Lady (Vanessa virginiensis): Uncommon — 9
West Coast Lady (Vanessa annabella): Uncommon — 5, 9
Red Admiral (Vanessa atalanta): Uncommon — 5, 10
Common Buckeye (Junonia coenia): Abundant — 4–7, 9–11
Lorquin's Admiral (Limenitis lorquini): Abundant — 6
California Sister (Adelpha bredowii): Abundant — 5–11
"California" Common Ringlet (Coenonympha tullia california): Abundant — 4–9
Common Wood-Nymph (Cercyonis pegala): Common — 5–8
Monarch (Danaus plexippus): Uncommon — 3, 6

Skippers

Propertius Duskywing (Erynnis propertius): Uncommon–Common — 3–6
Mournful Duskywing (Erynnis tristis): Uncommon–Common — 6–9
"Grinnell's" Pacuvius Duskywing (Erynnis pacuvius pernigra): Rare — 6
Two-banded Checkered-Skipper (Pyrgus ruralis): Uncommon — 4–5 (Windy Hill only)
Common Checkered-Skipper (Pyrgus communis): Uncommon — 1
"Dodge's" Western Branded Skipper (Hesperia [comma] colorado dodgei): Uncommon–Common — 7–9
Woodland Skipper (Ochlodes sylvanoides): Abundant — 7–10
Rural Skipper (Ochlodes agricola): Common — 6–7
Umber Skipper (Poanes melane): Uncommon — 6; Common 10