Everything changes. Even the monumental. The Earth rotates, stars shift, the sun and moon rise and set. A family member is missing at Christmas dinner. A dog no longer is at the door, tail bouncing with ecstasy.

For me, only a few things stay the same and show no sign of changing. And I depend on them. They help me stay rooted. One is the mountain to the east of my Shelburne Falls house, Mount Massamet, elevation 1,588 feet. Another is the stone tower at its top, a fixture of the Shelburne Falls landscape, tiny in comparison to the mountain, slighter than a stem on an apple.

But up close, it rises six stories high, and at the apex of its dark, gothic, stone spiral staircase is a 360-degree view. Monadnock to the northeast. Haystack and Mount Snow to the north. Shelburne Falls and the 3,491-foot Greylock to the west. The Holyoke Range and UMass to the south.

I used to live on Patten Hill, a foothill of Mount Massamet. We lived in a shepherd’s cottage just a few yards from the entrance to the High Ledges nature area. I’d walk with my baby daughter and husband down a rolling path through woods and fields to the Ledges.

Halfway there, a huge sycamore tree thrust a thick arm over the path, and families rested there, taking pictures of their children propped up on the gnarly arm.

Before the tree you’d pass strange-looking trees in an orchard, where native Ellsworth Barnard grafted the nearly extinct chestnut trees onto apple trees. Ellsworth — known as Dutchy — grew up on the mountain, happily filling up his lunchbox on the way to school with chestnuts before a blight called Cryphonectria parasitica decimated them.

He later lived all over the country, working as an English professor in colleges including Williams, UMass and University of Chicago. (He lost his position at Alfred University when he wouldn’t sign a statement that he was not a Communist.) Barnard wrote about his Patten Hill childhood in a three-book series. I remember him describing in one traveling down to Arms Academy — the little brick school in Shelburne Falls that West County students went to until 1967 — on a sled. Sheep kept the slopes bare of trees back then. At the end of the school day, he’d walk right back up the mountain. Russell Davenport of Davenport’s Maple Farm made the same trip up and down the mountain; his record was 15 minutes down. Often Davenport would see the same animals day after day — deer, bobcat and cougar — almost as if they were waiting for him.

The High Ledges woods road ends at a rocky outcropping with a 180-degree view of Shelburne Falls (you can see the brick Arms Academy from here), Catamount Mountain in Colrain, the Deerfield River, and, on a clear day, Greylock, with its own tower. A stone fireplace and chimney sits just 100 feet uphill of the ledges, the only sign of the summer house Dutch and his wife lived in for decades when not in Amherst or halfway across the country. The couple gave the property to Audubon, which knocked down the house. I had fantasies of renting it for a week during the summers and hoped it would be available, but I didn’t contact Audubon and then it was gone. Things change.

Barnard used to lead nature walks here, when I lived on Patten Hill in the 90s, and he was the first person to show me the lovely and rare lady slippers and pitcher plants. During one of the spring walks he led, I heard a familiar three-note bird call dropping in pitch. “What is that?” I asked him. “A chickadee,” he answered gently. I was embarrassed to not know the call, as I only had known chickadees to sing “chicadee-dee-dee.” Now every time I hear of it, I think of him.

There used to be a marked trail from High Ledges down to the Arms Cemetery beaver pond just north of Route 2, but it’s no longer marked. In about 2005, I had the brilliant idea of taking some of my 24 Chinese students (here for three weeks of English immersion) on a walk from my house in Shelburne Falls, up the steep path to the tower, over a mile or so to High Ledges, down to the beaver pond, across it on the dam, and back to my house. The two Chinese chaperones were eager to do it, as were a few students, so we started up one July morning. These were city dwellers, and the men had on brown leather shoes seen on Wall Street but almost never in Shelburne Falls. But they appreciated it all — the lung-splitting trek past the Shelburne Falls water tower, the view out the tower windows, the leisurely picnic at High Ledges, turkey vultures floating over the evergreens. Even the soggy trek across the Arms Cemetery beaver dam, water seeping over their shoes with every step. Not a word of complaint from anybody.

One of my favorite tower experiences was hiking to it with the entire Buckland-Shelburne Elementary student body one fall in about 2011. Children and teachers approached it from two directions, from Route 2 and the water tower to the west and from Davenport’s Farm to the south. The students climbed the stone stairs and gazed at the spectacular views. Many had never been there before. I enjoyed seeing the tower and view through their enthusiastic eyes.

Since moving down the mountain, my family and I don’t have High Ledges and the tower on our minds as much. Still, my husband hikes and runs the mountain with a Shelburne Center friend of his. And the mountain was featured in his own sort of marathon this summer. He got up at 7. Walked the dog. Drove to Mount Monadnock, about 90 miles northeast of our house. He hiked it. Drove back to Shelburne Falls. Walked the dog. Ran up Mount Massaemet to the tower with his running friend. Walked the dog. Drove one hour to Mount Greylock. Hiked it. Drove home. Walked the dog. It was 7 p.m. and he’d climbed 5,000 feet during the day and drove for five hours. And topped three mountains.

The tower was built in 1909 and is the oldest continually active lookout in Massachusetts, if not the U.S. Resident Roy Merrill built it for $1,720, cutting granite from the mountaintop and dragging it to the site with an ox, according to Davenport’s book on the area, “Sunny Side of Mount Massamet.” It has three-foot-thick walls at the bottom. Nelson “Spence” Woodward worked there as a firewatcher from 1910 through 1936, Davenport reported. Woodward invited everyone up to the tower, cooking for them in a shack built at the tower’s base. He would report 75 to 150 fires a year, according to Davenport.

A fire watcher still works in the glass cabin at the top during fire season, employed by the state Bureau of Forest Fire Control. If you have a fire permit in the tower’s 15-mile purview, he knows it.

The tower looks exactly as it did in 1909, except for the glass cabin. Beautiful, light-colored stones, the dark spiral staircase, and the view of mountains, river, sky. The good earth. Immovable. Dependable. There for you.