Take raw, unlit strands on a long-haul route across our privately owned California network. Bring your own optics, light it your way, and scale to whatever capacity your business demands.
Single-mode
Dedicated strands
Your optics
Light it your way
Diverse paths
Route redundancy
Private
Physically isolated
Unlit · Customer-managed
99.5%
Underground
1,700+
Fiber strands
100+
Regen points
The direct path between California's two largest metros does not hug the coast. It runs inland through the Central Valley — the flat, buildable ground where conduit goes in straight and stays reachable. That run is what long-haul dark fiber means here: all 11 markets Vast publishes sit on the line, and the plant under it is 99.5% buried.
99.5%underground
Almost none of this network is on poles, so it is out of reach of wind, ice, vehicle strikes and the outages that follow them.
1,700+strands
Strand count is what makes dark fiber available to hand over at all — a thin cable has nothing spare to give you.
100+sites
Regen and colocation sites along the route are where the optical budget is rebuilt, and where you can place your own equipment.
Long-haul dark fiber gives you dedicated physical infrastructure and total control — no shared electronics, no imposed limits. You decide how it's lit, scaled, and secured.
With 100+ regeneration points along the route: more flexibility, more redundancy, and less risk.
Bring your own optics and equipment. Choose your protocols, your capacity, and your upgrade path.
No imposed ceiling. Scale by upgrading your own transceivers — not your contract.
A physically separate path with no shared electronics. Maximum isolation.
Lock in dedicated capacity you control for 10–20 years, with predictable long-term costs and none of the capex or maintenance burden of owning the infrastructure.
Long-haul dark fiber is optical fiber that has been installed in the ground, over intercity distances, but is not yet "lit" by a provider's transmission electronics. The glass is there; the light is not. When you take dark fiber from Vast Networks, you take the physical strands themselves across our 5,000+ route miles of privately owned fiber in California — plant that is 99.5% underground, carrying 1,700+ strands, with 100+ regeneration and colocation points along the way — then light them with your own optics. The result is a private network you control end-to-end, with capacity and protocols that answer to you, not your carrier's product catalog.
With lit fiber, the provider owns the electronics on each end and delivers a managed circuit at a defined speed — simple and turnkey. With dark fiber, you own those electronics, which means you decide the bandwidth, the framing, and when to upgrade. Lit fiber is the right choice when you want a fully managed service; dark fiber is the right choice when you need maximum control, privacy, and a capacity ceiling limited only by your own hardware.
Because you supply the optics, the same pair of fibers can carry a few gigabits today and hundreds of gigabits — or terabits — tomorrow. Modern coherent and DWDM transceivers let you multiply capacity simply by swapping transponders, with no change to your underlying agreement. That makes dark fiber uniquely future-proof: you grow on your own timeline, at the speed your technology allows, without renegotiating bandwidth every time demand spikes.
A dark fiber path is physically separate, with no shared provider electronics in line. Your traffic never mingles with anyone else's, and you can apply your own encryption and security policies across the entire route. For carriers, data centers, universities, hospitals, and organizations with strict compliance requirements, that physical isolation is often the deciding factor.
Dark fiber is built for organizations that want to operate like their own network. Carriers and wholesale providers use it to extend reach; data centers and cloud platforms use it for high-capacity interconnect; research universities, healthcare systems, and latency-sensitive trading operations use it for control and isolation. We design the path and monitor the physical plant 24/7 — you own everything that rides on top of it.
Common questions about dark fiber, capacity, equipment, and availability.
Dark fiber is optical fiber that has been installed but is not "lit" by the provider's electronics. Long-haul dark fiber is the same thing over intercity distances rather than inside one metro. When you take dark fiber from Vast Networks, you hold the physical glass itself and supply your own optics and equipment to light it — giving you a private network with capacity and protocols entirely under your control.
With lit (dedicated) fiber, we provide the transport electronics and deliver a managed service at a set speed. With dark fiber, you control the electronics on each end, so you decide the capacity, the protocols, and the upgrade path. Dark fiber offers maximum control and a near-unlimited capacity ceiling; lit fiber offers a fully managed, plug-and-play experience.
Because you own the optics, the ceiling is set by your equipment rather than your contract. With modern coherent and DWDM transceivers, a single dark fiber pair can carry hundreds of gigabits and scale into the terabits — and you can upgrade capacity simply by changing your own transponders.
Yes. Dark fiber is the physical layer only, so you provide and manage the optics and networking gear on each end. This is what gives dark fiber its flexibility and privacy. Our team can advise on path design and reach, and our NOC monitors the physical plant 24/7.
Dark fiber is a physically separate path with no shared electronics, which is why carriers, healthcare systems, research networks, and security-conscious enterprises choose it. Your traffic never traverses shared provider equipment, and you can apply your own encryption and security policies end-to-end.
99.5% of it. That number matters more than it sounds: aerial fiber shares poles with power and is exposed to wind, ice, vehicle strikes and third-party work, which is where a large share of fiber cuts come from. Buried plant in private conduit takes that whole category of risk off the table, and it is the reason we quote the figure at all.
An optical signal weakens over distance, so it has to be regenerated at intervals along a long-haul route. Those sites are also colocation space: with 100+ of them across the network, you have that many places to put your own equipment, hand off to another carrier, or split a route for redundancy — which is what turns a single long span into a network you can design around.
We operate 5,000+ route miles of privately owned, underground fiber across California, with point-to-point, multi-site, and diverse/protected path options. Share your endpoints and routing requirements and we will map the available paths and provide a quote.
Dark fiber hands you an asset and a set of responsibilities at the same time. These pages work through whether that trade is right for your team.
Written for the market rather than templated onto it. Availability is still confirmed per address.
Tell us your endpoints and routing needs. We'll map available dark fiber paths and put together a quote.