3421 4th St

Boulder, CO 80304

$6,800,000
Price
6
Beds
5,198 Sq. Ft.
$1,308 / Sq. Ft.
5,198
Sq. Ft.
$1,308
per Sq. Ft.
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Open: 5/24 12:00PM - 04:00PM
Open: 5/24 12:00PM - 04:00PM

Description

Newlands Sanctuary on Mt. Sanitas Open Space Step onto the 600-square-foot deck and look up. Mt. Sanitas rises 1,300 feet from your backyard gate, private access to the Goat Trail. No driving. No parking. Just you, your coffee, and maybe a 4-legged friend who will make sure you don't skip it. This premier property is one of eight homes backing directly to open space. In 21 years, only one has changed hands. Hidden behind a 70-yard tree-lined driveway on a 0.6-acre lot (2.5x standard), this is widely...Newlands Sanctuary on Mt. Sanitas Open Space Step onto the 600-square-foot deck and look up. Mt. Sanitas rises 1,300 feet from your backyard gate, private access to the Goat Trail. No driving. No parking. Just you, your coffee, and maybe a 4-legged friend who will make sure you don't skip it. This premier property is one of eight homes backing directly to open space. In 21 years, only one has changed hands. Hidden behind a 70-yard tree-lined driveway on a 0.6-acre lot (2.5x standard), this is widely regarded as one of Boulder's best addresses, served by top rated schools. The 5,200-square-foot residence features 20-foot ceilings with west-facing glass framing Mt. Sanitas, white oak floors, two fireplaces, and a library overlooking the property's seven heritage apple trees. Six bedrooms plus office (convertible seventh) include three distinct suites: the primary en-suite with a stunning view; a garden-level walkout in-law addition (2005, 12' ceilings) with separate entrance, private patio, and dedicated office-ideal for multigenerational living or guests-plus a basement suite with whirlpool bath. Outside you will discover a deep wrap-around porch beneath a 60-foot silver maple, flower and vegetable gardens, and the historic Silver Lake Ditch with 12,000 gallons daily water rights. Sundance Film Festival arrives January 2027, venues minutes away providing a chance at an incredible rental income opportunity and under the Augusta Rule, 14 days of rental income may be tax-free. Roof replaced 2019. New carpet. Heated two-car garage. No HOA. No covenants. For those who know Newlands: this is the privacy, the lot, the view, and the trail access that almost never comes to market. For those discovering Boulder for the first time: welcome to the neighborhood the locals covet most.
  1. Listed by Kathleen Haas • Colorado Realty 4 Less, LLC
    P: (970)-531-7448 C: (970)-531-7448 KathyHaas@ColoradoRealty4Less.com

Property Details for 3421 4th Street

Locale
Boulder
Description 1
House

Open Houses

Sunday, May 24th12:00 PM - 4:00 PM
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Saturday, May 30th12:00 PM - 4:00 PM
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Sunday, May 31st12:00 PM - 4:00 PM
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LISTING UPDATED: 05/20/2026 04:16 AM

Property Details for 3421 4th Street

StatusActive
MLS #1053821
Days on Compass72
Taxes$26,030 / year
HOA Fees-
Condo/Co-op Fees-
Property TypeSingle Family
MLS TypeResidential / Single Family Residence
Year Built1990
Lot Size0.60 AC / 26,136 SF
CountyBoulder County
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Location

Listing Courtesy of Colorado Realty 4 Less, LLC, Kathleen Haas
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Building Information for 3421 4th Street

Stories-Year Built1990Building Size-Lot Size0.60 AC / 26,136 SF

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$36,054 per month

30 year fixed, 6.36% Interest

Principal and Interest

$33,885

Property Taxes

$2,169

HOA Dues

$0

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Property Information for 3421 4th Street

Summary
Location and General Information
  • Road Access 2: City Street
  • Latitude: 40.04
  • Longitude: -105.29
Parking
  • Garage SqFt: 528
  • Total Parking: 2.00
  • Parking Features: Garage Door Opener, Attached
Taxes and HOA Information
  • Has HOA: No
  • HOA Fee: $.00
  • Legal Description: LOT 2 & NWLY TRI LOT 1 3403 FOURTH STREET
  • Tax Information: No
  • HOA2 Fee Amount: $0
  • Tax Year: 2025
  • Tax Annual Amount: $26,030
  • Parcel Number: R0108936
Property
Lot Information
  • Lot Improvements: Wooded, Evergreen Trees, Deciduous Trees, Sloping Lot, Abuts Ditch, Abuts Public Open Space, House Faces East, Paved, Water Rights Included
  • Lot Size Area: 26,072.00
  • Has Irrigation Water Rights: No
  • Has Improvements: No
  • Vegetation: Wooded
Property and Assessments
  • Total Finished Area Source: Other
  • Living SqFt: 3927
  • Above Grade Finished Area Source: 3927
  • Sq Ft Apx: 1271
  • Total Finished Area: 5022
  • Property Attached YN: No
  • Are Ditches Active: No
  • New Construction YN: No
  • Levels: Four
Utilities
  • Electric: Xcel
  • Sewer: Public Sewer
Interior and Exterior Features
Exterior Features
  • Construction Materials: Frame, Wood Siding
  • Exterior Features: Sprinkler System, Oversized Garage
Interior Features
  • Interior Features: Eat-in Kitchen, Separate Dining Room, Cathedral Ceiling(s), Open Floorplan, Walk-In Closet(s), Full Primary Bath, Tub+Shower Primary, Luxury Features Primary Bath, 5 Piece Primary Bath
  • Laundry Features: Gas Range, Down Draft, Self Cleaning Oven, Dishwasher, Refrigerator, Microwave, Disposal, Fire Alarm
  • Spa Features: Bath
  • Fireplaces 1: Two or More, Gas, Gas Log, Living Room, Family Room
  • All Bedrooms Conform: Yes
  • Full Bathrooms: 2
  • Half Bathrooms: 1
  • Rough-in Bathrooms: 0
  • Three Quarters Bathrooms: 2
  • Baths Full Additional: 0
  • Baths Full Basement: 1
  • Baths Full Upper: 1
  • Baths Full Main: 0
  • Baths Full Lower: 0
  • Baths Half Additional: 0
  • Baths Half Basement: 0
  • Baths Half Upper: 0
  • Baths Half Main: 1
  • Baths Half Lower: 0
  • Baths Three Quarters Additional: 0
  • Baths Three Quarters Basement: 0
  • Baths Three Quarters Lower: 0
  • Baths Three Quarters Upper: 1
  • Baths Three Quarters Main: 1
Room Information
Room 1
  • RoomDescription: Carpet
  • RoomLength: 12.0
  • RoomLevel: Upper
  • RoomType: Bedroom 2
  • RoomWidth: 12.0
Room 2
  • RoomDescription: Carpet
  • RoomLength: 11.0
  • RoomLevel: Upper
  • RoomType: Bedroom 3
  • RoomWidth: 13.0
Room 3
  • RoomDescription: Carpet
  • RoomLength: 11.0
  • RoomLevel: Upper
  • RoomType: Bedroom 4
  • RoomWidth: 15.0
Room 4
  • RoomDescription: Wood
  • RoomLength: 17.0
  • RoomLevel: Main
  • RoomType: Bedroom 5
  • RoomWidth: 23.0
Room 5
  • RoomDescription: Carpet
  • RoomLength: 15.0
  • RoomLevel: Lower
  • RoomType: Bedroom 6
  • RoomWidth: 13.0
Room 6
  • RoomDescription: Wood
  • RoomLength: 12.0
  • RoomLevel: Main
  • RoomType: Dining Room
  • RoomWidth: 13.0
Room 7
  • RoomDescription: Carpet
  • RoomLength: 14.0
  • RoomLevel: Main
  • RoomType: Great Room
  • RoomWidth: 19.0
Room 8
  • RoomDescription: Wood
  • RoomLength: 10.0
  • RoomLevel: Main
  • RoomType: Kitchen
  • RoomWidth: 15.0
Room 9
  • RoomDescription: Other
  • RoomLength: 10.0
  • RoomLevel: Lower
  • RoomType: Laundry
  • RoomWidth: 6.0
Room 10
  • RoomDescription: Wood
  • RoomLength: 13.0
  • RoomLevel: Main
  • RoomType: Living Room
  • RoomWidth: 15.0
Room 11
  • RoomDescription: Carpet
  • RoomLength: 15.0
  • RoomLevel: Upper
  • RoomType: Primary Bedroom
  • RoomWidth: 17.0
  • Room Features: Full Primary Bath, Tub+Shower Primary, Luxury Features Primary Bath, 5 Piece Primary Bath
Rental
Rental Information
  • Horse YN: No
  • Occupant Type: Owner

Property History for 3421 4th Street

DateEvent & SourcePriceAppreciation
Sep 16, 2004

Sold (Public Record)

Public Record #142926235

$1,750,000—
DateEvent & SourcePrice
09/16/2004

Sold (Public Record)

Public Record #142926235

$1,750,000

For completeness, we often displays two records for one sale: the MLS record and the public record.

Public Records for 3421 4th Street

Taxable ValueLand$196,356Additions$76,638Total$272,994
Tax Record2025$26,030 ($2,169 / month)
Home Facts
Beds4Baths3Total Finished SqFt5,022 SqFtAbove Grade Finished SqFt3,801 SqFtFinished Basement SqFt1,221 SqFtUnfinished Basement SqFt50 SqFtStories2Lot Size26,092 SqFtStyleSingle Family ResidenceYear Built1990Year Renovated1995Zoning1112CountyBOULDERAPN1461-24-2-13-002

Schools near 3421 4th Street

This home is within Boulder Valley Re 2 School District.
Rating
School
Type
Grades
Distance
Foothill Elementary School
Public - K to 5
Centennial Middle School
Public - 6 to 8
Boulder High School
Public - 9 to 12
University Hill Elementary School
Public - PK to 5
Rating
School
Distance
Foothill Elementary School
PublicK to 5

Centennial Middle School
Public6 to 8

Boulder High School
Public9 to 12

University Hill Elementary School
PublicPK to 5

School ratings and boundaries are provided by GreatSchools.org and Pitney Bowes. This information should only be used as a reference. Proximity or boundaries shown here are not a guarantee of enrollment. Please reach out to schools directly to verify all information and enrollment eligibility.

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More information about 3421 4th Street, Boulder, CO 80304

3421 4th Street is a single family home for sale in Boulder, CO 80304. This property was listed for sale on March 13, 2026 by Colorado Realty 4 Less, LLC, it's currently listed at $6,800,000. It has been on the market for a total of 72 days and was last sold on September 16, 2004. This listing's school district is Boulder Valley Re 2 School District. Nearby schools include Foothill Elementary School, Centennial Middle School and Boulder High School. 3421 4th Street is a 6-bed, 5-bath, 5,198 sqft single family home built in 1990.

No guarantee, warranty or representation of any kind is made regarding the completeness or accuracy of descriptions or measurements (including square footage measurements and property condition), such should be independently verified, and Compass, Inc., its subsidiaries, affiliates and their agents and associated third parties expressly disclaims any liability in connection therewith. Photos may be virtually staged or digitally enhanced and may not reflect actual property conditions. Offers of compensation are subject to change at the discretion of the seller. No financial or legal advice provided. Equal Housing Opportunity. Subject to change at any time. Compass, Inc., its subsidiaries, affiliates and their agents and associated third parties make no guarantee, warranty or representation regarding the accuracy of any waterfront feature, water view or waterfront view.

Listing Courtesy of Colorado Realty 4 Less, LLC, Kathleen Haas

Based on information submitted to the MLS GRID as of 05/20/2026 04:16 AM. All data is obtained from various sources and may not have been verified by broker or MLS GRID. Supplied Open House Information is subject to change without notice. All information should be independently reviewed and verified for accuracy. Properties may or may not be listed by the office/agent presenting the information. Properties displayed may be listed or sold by various participants in the MLS. IDX information is provided exclusively for consumers’ personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. The data is deemed reliable but is not guaranteed by MLS GRID. Use of the MLS GRID data may be subject to an end user license agreement prescribed by the applicable MLS of the Member Participant, if any, and as amended from time to time.