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Blue Mountains
Region profile

Blue Mountains

Blue Mountains is an ecoregion in northeastern Oregon, southeastern Washington, and western Idaho, characterized by a severe, mid-latitude climate with volcanic origins, featuring diverse elevations, various vegetation zones from grasslands to alpine meadows, and main activities including forestry, recreation, and cattle grazing.

Zone

Interior

Common Name

Blue Mountains

CEC Level III Code

6.2.9

CEC Level II Code

6.2 Western Cordillera

Overview

About This Region

The Blue Mountains ecoregion, spanning parts of Oregon and Idaho, offers diverse habitats vital for pollinators. These mountainous areas, including national forests and wildernesses, provide a range of flowering plants like Blue Giant Hyssop and Goldenrod (late-season blooms) that supply essential nectar and pollen. Pollinators face challenges from habitat fragmentation and land-use changes. Conservation efforts in this region are crucial to supporting species and ensuring successful pollination for the ecosystem.
Blue Mountains
https://www.inaturalist.org/photos/457828441 Photo: (c) Susan, some rights reserved (CC BY-NC) | CC-BY-NC | iNaturalist

Region facts

At a glance

AliasesBlue Mountains, CEC 6.2.9
Geographic Range
The Blue Mountains ecoregion is situated primarily in northeastern Oregon, with small areas extending into southeastern Washington and western Idaho.
Climate SnapshotThe Blue Mountains ecoregion has a severe, mid-latitude climate with continental and Mediterranean influences, marked by warm, dry summers and cold winters, with mean annual temperatures ranging from approximately -1°C to 10°C and highly variable precipitation (220 mm to over 2,050 mm).
Terrain ProfileThe Blue Mountains ecoregion is mostly volcanic in origin, with elevations ranging from 305 masl to over 3,000 masl, and is characterized as generally not as high and considerably more open compared to neighboring ecoregions.
Vegetation CoverVegetation in the Blue Mountains ranges from low-elevation grasslands and juniper woodlands to forests of ponderosa pine, Douglas fir, and grand fir, with higher elevations featuring subalpine fir, Engelmann spruce, whitebark pine, and alpine meadows.
Wildlife HabitatThe Blue Mountains ecoregion supports diverse species including Rocky Mountain elk, mule deer, black bear, and various fish like chinook salmon and rainbow trout, alongside numerous bird species such as the golden eagle and pileated woodpecker.

Eco snapshot

What shapes this region

Climate pattern

  • Mountain terrain creates many microclimates (small local weather differences) based on slope, shade, and elevation.
  • Spring can arrive earlier in valleys and later on higher, shaded slopes.
  • Many sites experience a drier summer period, so drought-tolerant natives can be important.

Vegetation profile

Vegetation in the Blue Mountains ranges from low-elevation grasslands and juniper woodlands to forests of ponderosa pine, Douglas fir, and grand fir, with higher elevations featuring subalpine fir, Engelmann spruce, whitebark pine, and alpine meadows.

Wildlife profile

The Blue Mountains ecoregion supports diverse species including Rocky Mountain elk, mule deer, black bear, and various fish like chinook salmon and rainbow trout, alongside numerous bird species such as the golden eagle and pileated woodpecker.

Why pollinators matter here

  • Pollinators support seed and fruit set for many wild plants that feed birds and other wildlife.
  • Meadow and edge habitats can be especially important “flower zones” in forested landscapes.
  • A long season of blooms helps pollinators build healthy populations across the year.
  • Pesticides and loss of diverse flowering habitat can reduce local pollinator success.

Seasonal timing

Planting seasons

Timing varies by microclimate; use this as a flexible guide.

Seasonal timing

  • Early season: Focus on early-blooming natives and flowering shrubs; watch for late cold snaps.
  • Main season: Plant and maintain a mix of flowers that overlap bloom times.
  • Late season: Prioritize late-blooming plants and seed heads; reduce watering needs with mulch and drought-tolerant choices where appropriate.

Quick seasonal checklist

  • Add at least 3 bloom windows (early, mid, late).
  • Plant in clumps (easier for pollinators to find).
  • Keep a shallow water source (like a dish with stones) during hot/dry periods.
  • Leave some areas undisturbed for nesting and overwintering.

Yearly needs

Pollinator calendar

What pollinators need throughout the year, and what to do about it.

Late winter / early springEarly nectar and pollen; safe shelterPlant/keep early bloomers; delay heavy cleanup; avoid pesticides
SpringSteady bloom; nesting sites starting upAdd native flowers in clumps; leave some bare soil; add a small brush/leaf corner
SummerReliable nectar during heat/dry spells; waterChoose drought-tolerant natives; provide a shallow water dish; keep blooms continuous
Late summer / fall“Finish-line” flowers; energy for overwinteringPlant late bloomers; avoid deadheading everything; leave seed heads and stems
WinterProtected shelter; undisturbed habitatLeave leaves/stems; avoid cutting everything back; keep pesticide-free practices year-round

Seed mix concept

A Billion Small Steps Seed mix

A simple way to plan is to think in three layers that cover the whole season:

Spring starter

Early bloomers (including early perennials and, where appropriate, flowering shrubs nearby).

Summer bridge

Reliable mid-season flowers that handle typical summer conditions.

Fall finisher

Late-season asters/goldenrods/rabbitbrush-type blooms to carry pollinators into the end of the season.

What You Can Do

Make a difference for native habitats.

Turn this knowledge into action. Whether you plant a single pot or a whole garden, you are building a vital bridge for local biodiversity.

Join the movement to restore our shared habitats.

Native plants

Plants that thrive in this region

Alders (*Alnus* spp.)

Alders

Alders are fast-growing trees in the genus Alnus that are especially useful in damp spots and along edges where you want quick cover and early-season pollen for insects.

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Asters (*Symphyotrichum* spp.)

Asters

Asters are late-season wildflowers that bring a burst of daisy-like blooms when many gardens are winding down, making them a reliable choice for pollinator-friendly planting.

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Birches (*Betula* (genus))

Birches

Birches are graceful trees in the genus Betula, known for their often light-colored bark and early-season pollen and catkins that support springtime insects.

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Blueberries & huckleberries (*Vaccinium* (genus))

Blueberries & huckleberries

Blueberries and huckleberries (genus Vaccinium) are berry-producing shrubs with spring flowers that can support pollinators and later feed people and wildlife—great for gardens, schoolyards, and even large containers.

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Clovers (*Trifolium* spp.)

Clovers

Clovers are small, easygoing plants in the genus Trifolium that can add nectar and pollen to gardens, lawns, and pots while helping cover bare soil.

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Fireweed (*Chamerion* spp.)

Fireweed

Fireweed is a tough, fast-growing wildflower in the genus Chamerion that brings bright pink blooms and lots of pollinator activity to sunny, open spaces.

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Fleabanes (*Erigeron* spp.)

Fleabanes

Fleabanes (genus Erigeron) are easygoing wildflowers with daisy-like blooms that can brighten gardens, schoolyards, and balcony pots while offering steady nectar and pollen for many small pollinators.

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Goldenrods (*Solidago* spp.)

Goldenrods

Goldenrods are tough, sunny wildflowers in the genus Solidago that light up late-season gardens with golden blooms and provide reliable nectar and pollen when many other flowers are fading.

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Kinnikinnick (Arctostaphylos spp.)

Kinnikinnick

Kinnikinnick is a tough, low-growing evergreen groundcover in the genus Arctostaphylos (often called bearberry) that forms a tidy mat and offers small spring flowers followed by red berries.

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Manzanitas (West) (Arctostaphylos spp.)

Manzanitas

Manzanitas are tough, beautiful western shrubs with urn-shaped flowers that can feed early-season pollinators and evergreen leaves that keep gardens looking good year-round.

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Poplars, aspens & cottonwoods (*Populus*)

Poplars, aspens & cottonwoods

Poplars, aspens, and cottonwoods (genus Populus) are fast-growing trees best known for their fluttering leaves and soft “cottony” seeds. They can support early-season pollinators with spring catkins, but they’re also big, thirsty, and often short-lived in small yards—so they’re best chosen with space and roots in mind.

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Rushes (*Juncus* spp.)

Rushes

Rushes are tough, grass-like wetland plants (genus Juncus) that thrive in damp soil and help create calm, sheltered habitat at the edges of ponds, rain gardens, and low spots.

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Sedges (*Carex* (genus))

Sedges

Sedges (genus Carex) are grass-like plants that form tidy clumps and thrive in many garden conditions, especially where soil stays a bit damp. They add texture, cover bare ground, and can support small wildlife by providing shelter and nesting material.

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Willowherbs (*Epilobium* spp.)

Willowherbs

Willowherbs (genus Epilobium) are easygoing wildflowers that pop up in sunny, open spots and offer simple, nectar-rich blooms that many small pollinators can use.

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Willows (*Salix* spp.)

Willows

Willows are fast-growing trees and shrubs in the genus Salix that offer some of the earliest pollen and nectar of the year, making them a strong choice for pollinator-friendly yards, parks, and school grounds.

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Yarrow (*Achillea millefolium*)

Yarrow

Yarrow is a tough, easygoing wildflower that brings long-lasting blooms and steady pollinator visits to gardens, schoolyards, and even containers.

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Pollinators

Pollinators active in this region

Bee flies (Family Bombyliidae)

Bee flies

Adults visit flowers for nectar and can move pollen between blooms; their presence is a sign of diverse, functioning habitats.

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Bumble bees (Genus Bombus)

Bumble bees

Bumble bees are important pollinators of many wildflowers and garden plants, helping ecosystems and food crops reproduce.

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Dance flies (Family Empididae)

Dance flies

Many visit flowers for nectar and can move pollen between blooms while also playing important roles in local food webs.

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F_hoverfly-01.jpg

Flower flies / hoverflies

Adults visit flowers for nectar and pollen, and many species’ larvae help keep plant-eating pests in check.

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Geometer moths (Family Geometridae)

Geometer moths

Adults can help move pollen as they nectar at flowers, and their caterpillars are an important part of local food webs.

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Hawk / sphinx moths (Family Sphingidae)

Hawk / sphinx moths

They can move pollen between flowers while feeding on nectar, especially for blooms that open or scent up in the evening.

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Small nectar moths (micro-moths) (Multiple families (varies))

Small nectar moths (micro-moths)

Many small moths move pollen while feeding on nectar, supporting wild plants and garden blooms—especially in the evening and at night.

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Soldier flies (Family Stratiomyidae)

Soldier flies

Many adults visit flowers for nectar and can move pollen between blooms while feeding.

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Whites & sulphurs (Family Pieridae)

Whites & sulphurs

They visit a wide range of flowers for nectar and can help move pollen between blooms as they feed.

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