$6,800,000
Active

3421 4th Street

Boulder, CO 80304
Browse more homes in Boulder, CO
6
Beds
3.5
Baths
5,022
SqFt
1990
Built
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.
3421 4th Street
MORTGAGE CALCULATOR
$34,385
Estimate only — not a loan offer. Consult a lender for actual terms.

LISTING SNAPSHOT

Price$6,800,000
Bedrooms6
Full Baths2
Half Baths3
Inside Area (SqFt)5,022 sqft
Lot Size0.6 Acres
Year Built1990
MLS® NumberIR1053821
StatusActive
Property Tax26030
HOA/Condo/Coop FeesN/A

GENERAL

Acres0.6
Additional Property UseResidential
Attached GarageYes
Direction FacesEast
GarageYes
Garage Spaces2
LevelsThree Or More
ParkingOversized, Attached
Parking Spaces2
Property Sub TypeSingle Family Residence
SecuritySmoke Detector(s)
SewerPublic Sewer
SqFt Above3927
SqFt Below1095
SqFt Total5198
StyleContemporary
UtilitiesCable Available, Electricity Available, Natural Gas Available
Water SourcePublic
ZoningSFR

INTERIOR

AppliancesOven, Dishwasher, Disposal, Down Draft, Microwave, Refrigerator, Self Cleaning Oven
BasementDaylight, Full
CoolingCeiling Fan(s), Evaporative Cooling
Fireplace FeaturesFamily Room, Gas, Gas Log, Living Room
HeatingForced Air, Hot Water, Radiant
InteriorEat-in Kitchen, Open Floorplan, Vaulted Ceiling(s), Walk-In Closet(s)
Main Level Bedrooms1
Bathroom FullLevel - Basement
Bathroom HalfLevel - Main
Bathroom Three QuarterLevel - Main
BedroomDimensions - 15 x 17, Level - Upper, Description - Carpet
Dining RoomDimensions - 12 x 13, Level - Main, Description - Wood
Game RoomDimensions - 14 x 18, Level - Lower, Description - Other
Great RoomDimensions - 14 x 19, Level - Main, Description - Carpet
KitchenDimensions - 10 x 15, Level - Main, Description - Wood
LaundryDimensions - 10 x 6, Level - Lower, Description - Other
Living RoomDimensions - 13 x 15, Level - Main, Description - Wood
OfficeDimensions - 11 x 12, Level - Main, Description - Wood

EXTERIOR

Construction DetailsFrame, Wood Siding
FencingFenced, Partial
Lot FeaturesSloped, Wooded, Rolling Slope, Sprinklers In Front
Patio And PorchDeck, Patio
RoofComposition
Spa FeaturesBath
ViewMountain(s)
WaterviewMountain(s)

COMMUNITY

Financing Terms Available1031 Exchange, Cash, Conventional
RoadsPaved
School DistrictBoulder Valley RE 2

SCHOOLS

School DistrictBoulder Valley RE 2
Elementary SchoolFoothill
Middle SchoolCentennial
High SchoolBoulder

RECENT ACTIVITY

March 13, 2026Active
March 13, 20266800000

Listing courtesy of Colorado Realty 4 Less, LLC (9705317448)

Listing courtesy of Colorado Realty 4 Less, LLC KathyHaas@ColoradoRealty4Less.com



The content relating to real estate for sale in this Web site comes in part from the Internet Data eXchange ("IDX") program of METROLIST, INC., DBA RECOLORADO real estate listings held by brokers other than Colorado Realty 4 Less, LLC are marked with the IDX Logo. This information is being provided for the consumers' personal, non-commercial use and may not be used for any other purpose. All information subject to change and should be independently verified.

Comps

Limited comparable sales data available in this area.

Scroll to Top