The altar is in honor of his service dog, who died shortly before he became homeless.
It's set up near the corner of 7th and Virginia Street in San Jose.
Complete with his leash, harness, toys and photos, Miguel Maruyama's service dog 'Nacho' is being memorialized in a Dia de los Muertos altar, also known as an ofrenda.
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"The size of it is how much I love him and how much I miss him," Maruyama said. "I had him since he was born, he was with me almost 12 years."
Nacho was trained as a service dog to help with his now 19-year-old son's epilepsy.
"He was very important in our family, we miss him a lot," he said.
But the massive altar was built on Caltrans property, on the shoulder of an on-ramp to I-280 in San Jose.
Maruyama moved here last month with his son after losing his job, getting evicted, and Nacho dying.
"We recently we got notice from Caltrans that we are trespassing because we are on state property and they posted notice that the altar was going to be destroyed today, supposedly this morning," he said.
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Caltrans posted 'notice to vacate' signs around his campsite over the weekend, saying all personal property and camp debris needed to be removed by 8:30 a.m. on Monday morning.
"I was really sad about that because this is part of our tradition," he said. "Mexicans celebrate the Day of the Dead which is only a couple days away from now so I was really sad that they were going to come destroy the altar before the Day of the Dead," he said.
ABC7 News reached out to Caltrans and they said they have postponed clearing this site, for now, although they didn't specify if it was because of the Day of the Dead holiday.
"I'm really happy that the city is going to let me keep this for another week but I'm still like, I still don't know what I'm going to do next, I still don't know what's going to happen after a week because we still have to move out of here in one week and I still don't have nowhere to go," he said.
In the meantime, Maruyama is turning to community donations through GoFundMe for help getting back on his feet.