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If you have ever seen a Dumbarton Express bus on University Avenue, you have seen Union City on its sign. The city sits at the far end of Palo Alto's only bus across the bay, about 18 miles away in southern Alameda County. About 70,000 people live here, between Hayward to the north and Fremont to the south and east.
Union City is mainly a place where people live and commute, but it has more history than its freeway frontage suggests. It grew from two old villages, Alvarado and Decoto, with a sugar mill, a steel plant and railroad yards. Behind its neighborhoods rise big grassy hills with miles of trail. This guide covers the trip from Palo Alto, the town's story, the parks, food and why you might go.
Where Union City is and how far
Union City covers about 19 square miles on the east side of the bay. Interstate 880 crosses its western side and Mission Boulevard (Route 238) runs along the foot of the hills on the east. With Fremont and Newark, it forms the Tri-City Area. Alameda Creek forms part of its southern edge.
From downtown Palo Alto it is about 18 miles. Outside rush hour the drive takes about 25 minutes over the Dumbarton Bridge.
Getting there from Palo Alto
By car
Take University Avenue or Willow Road to the Dumbarton Bridge and follow Route 84 east. Turn north on Interstate 880 or take Decoto Road straight into town. Bridge tolls are charged only westbound, on the way home: $8.50 for a car in 2026, rising to $9.00 with FasTrak on January 1, 2027. There are no cash lanes. Our guide to bridges and tolls explains the payment options.
Dumbarton Express
The Dumbarton Express is the easiest car-free route, but only on weekdays. Its DB and DB1 lines start at Union City BART, stop at the Ardenwood Park and Ride in Fremont and cross the bridge to the Peninsula. Destinations include downtown Palo Alto, the Caltrain station, Stanford, Stanford Hospital, the VA hospital and Stanford Research Park. The operator lists service from about 5:30 a.m. to 8:45 p.m., with buses roughly every 20 minutes at peak times. The 2026 cash fare was $6.50; pay with Clipper or exact change. AC Transit administers the service. It does not run on weekends or on seven major holidays. Our East Bay travel guide has more.
BART
Union City station opened on September 11, 1972, with the first BART service. Look for the tile mosaics in the fare lobby, designed by the artist Jean Varda. Trains run north to Hayward, San Leandro and Oakland and south to Fremont. On weekends, the transit route from Palo Alto goes around the south end of the bay: Caltrain to Mountain View, VTA light rail to Milpitas, then BART north. It takes well over an hour. Union City Transit, started in 1974, runs local buses.
Alvarado, Decoto and the sugar mill
Ohlone people lived along Alameda Creek and Dry Creek for thousands of years. Shell mounds near the creek's sloughs held burials. In the Mexican era the land was part of large ranchos stretching from the bay to the hills.
The first American settlement came in 1850, when the brothers John and William Horner laid out a town and named it Union City after their Sacramento River steamboat, The Union. In 1854 it merged with nearby New Haven to form Alvarado, named for former Mexican governor Juan Bautista Alvarado. Alvarado served as Alameda County's first county seat until the seat moved to San Leandro in the 1850s. The town is California Historical Landmark No. 503. Farther east, Decoto grew up as a railroad stop after 1870.
Alvarado also has a national first. The California Beet Sugar Company began operating here in 1870, the first successful beet sugar factory in the United States. A marker at Dyer Street and Ratekin Drive, California Historical Landmark No. 768, notes the site. The plant was demolished in 1977. Later, the Pacific States Steel Company ran a large mill behind the present BART station. The American Licorice Company moved its West Coast operations to Union City in 1971.
By the 1950s, Hayward, Newark and the soon-to-be city of Fremont all eyed Alvarado and Decoto for annexation. The two villages chose to join each other instead and incorporated on January 13, 1959, reviving the Horners' old name. Tom Kitayama was the first mayor and stayed active in city politics until 1991. The population grew from about 6,000 in 1959 to about 70,000 by 2020. Freight and Amtrak trains still cross town on two rail lines. Long waits at crossings are part of local life.
The station district
The old steel mill land east of Union City BART is being redeveloped as the Station District, the city's planned downtown, with new housing and streets. BART has added a ground-level fare lobby and extra escalators. A future east-side entrance is planned to link the new neighborhood directly to the trains. A Dumbarton rail line with a Union City connection has been studied for years but has not been built.
Parks and trails
Dry Creek Pioneer Regional Park
Dry Creek Pioneer Regional Park climbs the hills directly behind Union City's eastern neighborhoods. It adjoins Garin Regional Park in Hayward. The East Bay Regional Park District manages the two together. The two parks cover about 5,857 acres with more than 20 miles of unpaved trails for hiking, horseback riding and, on many routes, mountain biking. Dogs are allowed on leashes no longer than 6 feet. Summits reach about 1,500 feet, with views across the whole south bay to the Peninsula hills. Garin hosts an apple festival in its heirloom orchard in late summer. The grass turns gold by June, so spring is the best season. Our dog-friendly hikes guide lists more options.
Flight 93 Memorial
Sugar Mill Landing Park, a strip of grass on Dyer Street near the old sugar mill site, holds the Bay Area Flight 93 Memorial. It has 40 large granite stones, one for each passenger and crew member of United Airlines Flight 93, which was bound for San Francisco on September 11, 2001. It was the first completed monument in the country honoring the flight.
Nearby
Just south, Fremont's Quarry Lakes and the Coyote Hills shoreline are a short drive away. For a bigger climb, Mission Peak rises above Fremont.
Food and shopping
Like the rest of the Tri-City Area, Union City eats well for its size. Shopping centers along Alvarado-Niles Road, Decoto Road and Union City Boulevard hold Filipino bakeries, Indian and Afghan restaurants, Chinese and Vietnamese noodle shops, taquerias and Asian supermarkets. A large shopping center beside Interstate 880, built in 1999 on the site of an old drive-in theater, adds chain restaurants and stores. For more variety, Fremont's restaurant districts are minutes away.
Why a Palo Alto resident might go
- A car-free link to BART. On weekdays the Dumbarton Express to Union City is the quickest transit route from Palo Alto to the East Bay rail network.
- Big hills without the crowds. Dry Creek and Garin feel far emptier than Mission Peak.
- Local history. The sugar mill and Alvarado markers tell an industrial story most Peninsula residents never hear.
- Everyday food. Tri-City restaurants offer cooking that is harder to find in Palo Alto. If you stay over for an early hike, you can compare hotels in Union City and Fremont.
Good to know
- The Dumbarton Express does not run on weekends or major holidays.
- Bridge traffic heads west in the morning and east in the evening; travel against it when you can.
- The hill parks get hot and have little shade in summer. Carry water.
- Expect freight train delays at rail crossings in town.
Frequently asked questions
How do I get from Palo Alto to Union City without a car?
On weekdays, take the Dumbarton Express. Its DB and DB1 lines run between Union City BART and the Peninsula, serving Stanford Research Park, Stanford, downtown Palo Alto and the Caltrain station. Service runs from about 5:30 a.m. to 8:45 p.m., with buses roughly every 20 minutes at peak times. The posted cash fare was $6.50 in 2026. There is no weekend service.
Does the Dumbarton Express run on weekends?
No. The Dumbarton Express runs weekdays only and does not run on New Year's Day, Presidents Day, Memorial Day, Independence Day, Labor Day, Thanksgiving or Christmas. On weekends, the transit route to Union City goes around the bay: Caltrain to Mountain View, VTA light rail to Milpitas and BART north.
Why is it called Union City?
John and William Horner founded a settlement here in 1850 and named it Union City after their Sacramento River steamboat, The Union. It later merged into the town of Alvarado. When Alvarado and Decoto incorporated together in 1959, they revived the Horners' name for the new city.
What is the Bay Area Flight 93 Memorial?
It is a memorial of 40 large granite stones in Sugar Mill Landing Park on Dyer Street, one for each passenger and crew member of United Airlines Flight 93. The plane was bound for San Francisco when it was hijacked and crashed in Pennsylvania on September 11, 2001. It was the first completed monument in the country honoring the flight.
What parks are in the hills above Union City?
Dry Creek Pioneer Regional Park sits right behind Union City's neighborhoods and adjoins Garin Regional Park in Hayward. Together the two East Bay Regional Park District parks cover about 5,857 acres with more than 20 miles of unpaved trails. Dogs must be on leashes no longer than 6 feet.