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Middle Rockies
Region profile

Middle Rockies

Middle Rockies is an ecoregion located mostly in southwestern Montana, eastern Idaho, and northern Wyoming, characterized by high alpine glaciated mountains, plateaus, and intermontane basins, with a severe, mid-latitude, humid continental climate and vegetation including Douglas fir, lodgepole pine, and aspen forests.

Zone

Interior

Common Name

Middle Rockies

CEC Level III Code

6.2.10

CEC Level II Code

6.2 Western Cordillera

Overview

About This Region

The Middle Rockies ecoregion, lacking the strong maritime influence of the Northern Rockies, features mountainous terrain with Douglas-fir, subalpine fir, and Engelmann spruce forests, and alpine areas. Pacific tree species are not dominant, and forests can be open. Factors affecting pollinators in this region include the high elevation, cold climate, and the specific forest species present which determine food availability and habitat suitability.
Middle Rockies
https://www.inaturalist.org/photos/296800692 Photo: (c) Christopher J. Earle, some rights reserved (CC BY-NC) | CC-BY-NC | iNaturalist

Region facts

At a glance

AliasesMiddle Rockies
Geographic Range
The Middle Rockies ecoregion is primarily located in southwestern Montana, eastern Idaho, and northern Wyoming, also encompassing the Black Hills in western South Dakota and northeastern Wyoming.
Climate SnapshotThe Middle Rockies ecoregion has a severe, mid-latitude, humid continental climate marked by warm to cool summers, severe winters, and mean annual precipitation of 621 mm, lacking the strong maritime influence of neighboring regions.
Terrain ProfileThe terrain of the Middle Rockies consists of high alpine glaciated mountains, plateaus, and glacial and lacustrine intermontane basins, with a variety of rock types and ages including volcanics, sedimentary, and metamorphic/igneous rocks.
Vegetation CoverCharacteristic vegetation includes forests of Douglas fir, lodgepole pine, aspen, subalpine fir, and Engelmann spruce, with alpine grasslands, meadows, krummholz, and ponderosa pine in the Black Hills, while foothills and valleys are partly wooded or covered with shrubs and grass.
Wildlife HabitatThe Middle Rockies ecoregion is home to diverse wildlife including black bear, moose, cougar, mountain goat, mule deer, and various bird species like the golden eagle and trumpeter swan.

Eco snapshot

What shapes this region

Climate pattern

  • Strong microclimates (small local weather differences) caused by elevation, slope direction, and proximity to water.
  • Late snowmelt can delay spring flowers in higher areas.
  • Wind exposure can be a major factor on ridges and open sites.

Vegetation profile

Characteristic vegetation includes forests of Douglas fir, lodgepole pine, aspen, subalpine fir, and Engelmann spruce, with alpine grasslands, meadows, krummholz, and ponderosa pine in the Black Hills, while foothills and valleys are partly wooded or covered with shrubs and grass.

Wildlife profile

The Middle Rockies ecoregion is home to diverse wildlife including black bear, moose, cougar, mountain goat, mule deer, and various bird species like the golden eagle and trumpeter swan.

Why pollinators matter here

  • Pollinators help wildflowers and shrubs set seed, supporting food webs.
  • Short growing seasons make “right plant, right place” especially important.
  • Diverse habitats can support diverse pollinators—if there are steady blooms.
  • Healthy pollinator habitat can improve resilience in gardens and restoration plantings.

Seasonal timing

Planting seasons

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

Seasonal timing

  • Early season: plant cool-tolerant natives and focus on early blooms as soon as soil can be worked.
  • Main season: add the bulk of flowering plants once nights are reliably milder (varies by site).
  • Late season: prioritize late-blooming natives and avoid stressing new plantings during hot/dry spells.

Quick seasonal checklist

  • Choose plants from multiple bloom windows (early/mid/late).
  • Group the same plant together in small clusters so pollinators can find them.
  • Add mulch thoughtfully (leave some bare soil for ground-nesting bees).
  • Keep a simple watering plan for new plants until established.

Yearly needs

Pollinator calendar

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

Late winter/early springEarly nectar/pollen; safe places to warm up and shelterLeave some leaf litter and stems; plan early-bloom natives; avoid spring pesticide “preventatives.”
SpringA steady ramp-up of blooms; nesting sitesPlant early bloomers; keep some bare, well-drained soil; add a small water source (shallow, with landing stones).
SummerContinuous flowers; water during dry spells; shade/refugeAim for “no gaps” bloom; plant in clusters; water new plantings; provide a few rocks/logs for shelter.
Late summer/fallHigh-energy nectar; late pollen; overwintering prepAdd late bloomers; avoid deadheading everything; leave seedheads and stems for habitat.
Winter or Dry SeasonProtected overwintering sitesDon’t over-tidy; leave stems standing; keep brush/leaf piles in a corner; plan next season’s additions.

Keystone plants

Keystone plants by season

Mix early, mid, and late bloomers so pollinators always find food.

Early Bloom

  • Serviceberry
  • Golden currant
  • Wild strawberry
  • Oregon grape
  • Lupine (regional species)
  • Rocky Mountain bee plant
  • Blanketflower
  • Yarrow
  • Purple coneflower
  • Beardtongue (regional species)

Mid-Season Bloom

Late-Season Bloom

  • Showy goldenrod
  • Smooth aster
  • Rabbitbrush (regional species)
  • Rocky Mountain blazing star

Seed mix concept

A Billion Small Steps Seed mix

A simple way to plan a pollinator patch here is to think in three layers:

Spring starter

Early bloomers (often shrubs and early perennials) to support the first active pollinators.

Summer bridge

Dependable mid-season flowers that carry the garden through peak activity.

Fall finisher

Late-season asters/goldenrods (and other late bloomers) to help pollinators fuel up before winter.

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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