What are some examples of metaphors and similes from Spoon River Anthology?

You're asking about a collection of almost 250 poems, so I can only give you a smattering of examples of metaphors--comparisons that do not use the word "like" or "as."

Poem 3: Ollie McGee

But what think you gnaws at my husband's heart?

The husband's guilt is compared to a mouse or other small animal that gnaws at his dead heart.

Poem 4: Fletcher McGee

She was a hunk of sculptor's clay,
My secret thoughts were fingers:
They flew behind her pensive brow
And lined it deep with pain.

Fletcher McGee is saying that his wife's face was like a hunk of clay that his secret thoughts molded as if they were fingers.

Poem 5: Robert Fulton Tanner

But a man can never avenge himself
On the monstrous ogre Life.

Tanner is comparing Life's challenges to a monstrous ogre.

Poem 7: Serepta Mason

MY LIFE'S BLOSSOM might have bloomed on all sides
Save for a bitter wind which stunted my petals

Serepta compares success in life to a flower's blossom.