Altitude does not shrink campsites
· 4 min · CampsiteFit
Here is a table that looks like a finding. Every bookable campsite at a published federal campground, banded by the campground's elevation, and the share of those campsites that take a 38 ft fifth wheel.
| elevation | sites | take 38 ft |
|---|---|---|
| under 1,000 ft | 40,573 | 62.1% |
| 1,000–3,000 ft | 24,503 | 41.4% |
| 3,000–6,000 ft | 18,525 | 28.2% |
| 6,000–8,000 ft | 15,715 | 30.7% |
| above 8,000 ft | 8,763 | 31.0% |
Read straight, it says something plausible about mountains: ground is steeper up there, benches are narrower, and a site cut into a slope is short. Your odds halve by 3,000 ft.
It is not true.
What happens when you hold the operator still
The same sites, banded the same way, but within one agency at a time.
| elevation | Forest Service | Corps of Engineers |
|---|---|---|
| under 1,000 ft | 47.0% | 71.9% |
| 1,000–3,000 ft | 31.7% | 67.8% |
| 3,000–6,000 ft | 35.0% | — |
| above 6,000 ft | 35.3% | — |
The Corps line barely moves: 71.9% under 1,000 ft and 67.8% between 1,000 and 3,000, across 36,000 sites. Whatever elevation is doing to campsite length, it is not doing much of it there.
The two dashes are not missing data, and they are not zero either. Of the 554 Corps campgrounds in this corpus, eight sit at or above 3,000 ft, holding 269 bookable sites between them — one campground above 6,000 ft, with 57 sites. A percentage computed on that would be a number about one campground wearing the costume of a rate, so the cell stays empty. That the Corps is almost entirely a low-elevation operator is itself the finding.
The Forest Service line has no gradient either, and it is the agency that actually spans the range — 275 campgrounds under 1,000 ft and 748 above 6,000. It dips in the middle and comes back, and its highest band is more generous than its middle one: 35.3% above 6,000 ft against 31.7% between 1,000 and 3,000. If altitude shortened sites, that is the one shape it could not produce.
So what was the first table measuring?
Who operates the campground.
The Corps of Engineers builds around flood-control reservoirs, which are low by construction — you do not dam a mountaintop. 28,967 of its sites sit under 1,000 ft, and Corps sites are the most generous in the country. The Forest Service is in the mountains almost by definition, and its sites are tighter for reasons that have nothing to do with the air.
Band by elevation and you are not measuring height. You are measuring the proportion of Corps campgrounds in each band, wearing height as a disguise.
This is the second one this week
The same shape caught us on driveway entry: pull-through sites look barely better than back-ins across the whole corpus, and inside every agency the gap is real and large. There the aggregate hid an effect. Here it manufactured one.
Both are the same arithmetic. A ratio computed over a mixed population tells you about the mixture as much as about the thing you asked, and this corpus is mixed in a way that is easy to forget: two agencies with very different building eras, very different terrain, and a four-to-one difference in how likely their sites are to take a long rig.
The habit that catches it is cheap. Before publishing a rate, split it by operator and see whether it survives. Twice this week it has not.
Where a long rig goes high anyway
The mountains are not closed to you, and the campgrounds that prove it are mostly in Arizona:
| Campground | State | Sites taking 38 ft | Elevation |
|---|---|---|---|
| Apache Trout Campground | Arizona | 64 | 9,059 ft |
| Hoyer Campground | Arizona | 69 | 8,279 ft |
| Canyon Point | Arizona | 100 | 7,677 ft |
| Table Mountain, Angeles | California | 61 | 7,327 ft |
| Logger Campground | California | 123 | 6,052 ft |
Apache Trout sits above 9,000 ft in the White Mountains and takes a 38 ft fifth wheel at 64 of its sites. Logger Campground, on the Sierra side of Lake Tahoe at 6,052 ft, takes one at 123. Nothing about the altitude shortened either of them.
What this site does with elevation
It shows it, because it matters: for grades on the approach, for water systems that freeze, for a season that opens in July rather than May. Every published campground carries a figure, sourced from USGS.
What it does not do is let elevation into the fit answer. Your rig fits a site or it does not, and the number that decides is the one the agency published for that site.
The elevations come from the USGS Elevation Point Query Service and the lengths from the Recreation Information Database, both public domain. Every campground page carries its own figure and links to its record. How it is measured explains why elevation never enters the answer.