CATOCTIN
SubstationMaryland · THE POTOMAC EDISON COMPANY
At a glance
CATOCTIN is an electric transmission substation in Maryland, on THE POTOMAC EDISON COMPANY's transmission network. It is classified as sub-transmission (138 kv) and connects 4 transmission lines. Substation proximity is one of the strongest speed-to-power signals for siting a datacenter — interconnection distance to an energized, high-voltage bus is often the binding constraint on time-to-energization.
Voltage & classification
Ownership
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #106100 | 138 kV | THE POTOMAC EDISON COMPANY | IN SERVICE | 10.9 mi |
| #123369 | 138 kV | THE POTOMAC EDISON CO | IN SERVICE | 12.7 mi |
| #135573 | 138 kV | THE POTOMAC EDISON COMPANY | IN SERVICE | 9.8 mi |
| #122601 | — | THE POTOMAC EDISON COMPANY | IN SERVICE | 0.7 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of CATOCTIN, ranked by DC Readiness. Sites this close to an energized substation carry a strong speed-to-power advantage.
| Site | Type | State | County | Voltage | Capacity | Queue wait | Score |
|---|---|---|---|---|---|---|---|
| DOUBS | Substation-Adjacent | MD | Frederick County | 500 kV | 1,000 MW | 5.3 yrs | 64.6 |
| TAP139322 | Substation-Adjacent | MD | Frederick County | 500 kV | 1,000 MW | 5.3 yrs | 64.3 |
| UNKNOWN123462 | Substation-Adjacent | PA | Adams County | 500 kV | 1,000 MW | 3.6 yrs | 63.0 |
| Forty West Landfill | Brownfield | MD | Washington | — | 2 MW | 5.3 yrs | 62.8 |
| UNKNOWN122896 | Substation-Adjacent | MD | Montgomery County | 230 kV | 300 MW | 5.3 yrs | 62.7 |
| CLARKSBURG | Substation-Adjacent | MD | Montgomery County | 230 kV | 300 MW | 5.3 yrs | 62.3 |
| Frederick County Landfill Solar | Brownfield | MD | Frederick | — | 2 MW | 5.3 yrs | 62.3 |
| UNKNOWN122905 | Substation-Adjacent | MD | Montgomery County | 230 kV | 300 MW | 5.3 yrs | 62.1 |
How does CATOCTIN compare with other substations in Maryland?
Maryland has 716 substation records in HIFLD, of which 186 carry a station name; the rest are unnamed tap points, risers and line ends. 46 named substations in the state are in CATOCTIN's 115–229 kV band (25% of named stations). 53 sit in a higher band. 9 named substations in Maryland operate at 345 kV or above. The highest voltage recorded in the state is 500 kV, and the state median is 138 kV.
Who owns the transmission lines at CATOCTIN?
The 4 connected lines listed above are owned by THE POTOMAC EDISON COMPANY, THE POTOMAC EDISON CO. Line voltages range from 138 kV to 138 kV. Their combined recorded length is about 34.1 miles.
How do candidate sites near CATOCTIN score?
The 8 highest-scoring candidate sites within about 25 miles range from 62 to 65 on the 0–100 DC Readiness scale. They fall in Frederick County, Adams County, Washington, Montgomery County. The Maryland average across 1,031 scored sites is 52.9. 314 of those Maryland sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is CATOCTIN substation?
CATOCTIN has a maximum voltage of 138 kV. That places it in the 115–229 kV band. The median named US substation in this dataset is 115 kV, so CATOCTIN is above the national midpoint.
How many transmission lines connect to CATOCTIN substation?
4 transmission lines terminate at or pass through CATOCTIN in the HIFLD line data. The connected lines listed here run at 138 kV. Together the listed lines cover about 34.1 miles.
Who owns CATOCTIN substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at CATOCTIN belong to THE POTOMAC EDISON COMPANY, and others to THE POTOMAC EDISON CO. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is CATOCTIN substation located?
CATOCTIN is in Maryland at 39.6134, -77.4098. The datacenter candidate sites closest to it are in Frederick County, Adams County, Washington.
Are there datacenter candidate sites near CATOCTIN substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of CATOCTIN. The highest-scoring is DOUBS at 65/100. Across Maryland, the average DC Readiness score is 52.9.
Other 138 kV substations in Maryland
- BETHESDA· 8 lines
- WYE MILLS· 6 lines
- REID· 5 lines
- FROSTBURG #1· 3 lines
- ANTIETAM· 2 lines
- EAST HAGERSTOWN· 2 lines
- HILLSBORO· 2 lines
- WALKERSVILLE· 2 lines
- All named substations in Maryland· 186 stations
- Datacenter candidate sites in Maryland· 1,031 sites
- Brownfield and retired plant sites in Maryland
- Substations by state
About this data
Source: HIFLD Electric Substations and Transmission Lines (U.S. Department of Homeland Security), as published June 29, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: GridCensus, “CATOCTIN substation, Maryland”, https://gridcensus.com/substations/maryland/catoctin-da4f9dc7 (data as of June 29, 2026).
Dataset updated . Screening estimates derived from public data sources.
Substation attributes are derived from public HIFLD / EIA infrastructure data and may lag real-world upgrades or retirements. Voltage and connected-line counts are screening figures — confirm available capacity and interconnection terms directly with the operating utility and ISO.
Go deeper than the public screen
Every site and score for CATOCTIN substation, Maryland is free to browse. Pro adds Watchtower on 25 sites, alerts when new candidate sites, datacenters or interconnection-queue requests appear in your markets, score and capacity history, and CSV export. Enterprise adds team seats, weekly data files for all 147,272 sites, the REST API and an MCP server for AI tools.