Yosemite National Park trail distances correspond to map distances

Yosemite National Park trail signs are classic Sierrana: thick steel plate hand cut by torch, rusted steadiness, upright after countless winter snows. The trail mileage on some signs is obviously incorrect. In general, how do the trail distances correspond to map distances.

To make the comparison, I recorded the trail distances at each junction on a route from Crescent Lake to Glacier Point trail head. A total of 7 junctions were passed, each with three sign posts [the junction numbers in the tabulation below are numbered along the route as passed] Map distances were computed in TOPO based on USGS 7.5-minute quadrangles at 4x magnification. Distances to place names that involved more than one route were omitted.

Overall the results show that trail signs and map distances correspond very well. Of the 46 pair wise comparisons possible, the majority of instances have the trail sign distances slightly longer than the map distances, but only by a minor fraction: 5.5% longer distance. Some distances were inconsistent by as much as 20%

	DESTINATION	SIGN	TOPO	diff.
Junction 1	Johnson Lake	4.5	4.15	0.35
	Royan Arch Lake	5.7	5.65	0.05
	Buck Camp	6.4	6.48	-0.08
	Chiquita Pass	11.2	11.10	0.10
	Wawona	8.2	7.82	0.38
	Deer Camp	4.7	4.52	0.18
	Bridalveil Camp	7.6	7.49	0.11
	Buena Vista Lake	6.2	5.93	0.27
	TOTALS	54.5	53.14	1.36
Junction 2	Buck Camp	7.1	7.99	-0.89
	Wawona	8.6	7.97	0.63
	Chiquita Pass	11.8	12.40	-0.60
	Buena Vista Lake	5.4	5.35	0.05
	Deer Camp	4	3.11	0.89
	Bridalveil Camp	6.7	5.93	0.77
	TOTALS	43.6	42.75	0.85
Junction 3	Wawona	8.5	7.97	0.53
	Buena Vista Lake	6.4	6.20	0.20
	Buck Camp	7.9	8.05	-0.15
	Chiquita Pass	12.7	12.57	0.13
	Deer Camp	3.2	3.11	0.09
	Bridalveil Camp	6	5.93	0.07
	TOTALS	44.7	43.83	0.87
Junction 4	Buena Vista Lake	7.7	7.50	0.20
	Wawona	9.8	9.27	0.53
	Buck Camp	9.2	9.31	-0.11
	Chiquita Pass	14	13.83	0.17
	Deer Camp	1.9	1.81	0.09
	Ostrander Lake	6.4	7.01	-0.61
	Bridalveil Camp	4.7	4.62	0.08
	TOTALS	53.7	53.35	0.35
Junction 5	Deer Camp	4.3	4.32	-0.02
	Wawona	12.3	11.78	0.52
	Buck Camp	10.5	11.82	-1.32
	Chiquita Pass	16.6	16.34	0.26
	Ostrander Lake	3.9	4.05	-0.15
	Bridalveil Camp	2.2	2.11	0.09
	TOTALS	49.8	50.42	-0.62
Junction 6	Deer Camp	5.7	4.88	0.82
	Buck Camp	11.8	12.34	-0.54
	Wawona	13.7	12.34	1.36
	Ostrander Lake	5.3	4.78	0.52
	Bridalveil Camp	1.4	1.55	-0.15
	TOTALS	37.9	35.89	2.01
Junction 7	Ostrander Lake	4.5	4.46	0.04
	Deer Camp	4.9	5.2	-0.30
	Wawona	12.9	12.66	0.24
	Buck Camp	12.4	12.7	-0.30
	Chiquita Pass	17.1	17.02	0.08
	Glacier Point Road	1.7	1.42	0.28
	Bridalveil Camp	1.6	1.87	-0.27
	TOTALS	55.1	55.33	-0.23