Print it. Bag it. Bring it.Phones die, screens crack, and most of this water has no signal. Print this map, fold it into a zip-top bag or dry bag with your license, and you have a backup your electronics can’t give you. Every marker is numbered so you can say exactly where you are.
| # | Point | Type | Lat, Lon | Notes |
|---|---|---|---|---|
| 1 | Bartlett Point Road Bridge County road crossing at Howell Ranch | Bridge crossing | 43.99710, -114.02214 | |
| 2 | USGS gauge — Big Lost River at Howell Ranch near Chilly Station 13120500 | USGS gauge | 43.99833, -114.02111 | |
| 3 | Big Lost River — Upper IDFG access site · state endowment land | Access / boat ramp | 44.01782, -113.98930 | |
| 4 | Old Chilly Road Bridge County road crossing | Bridge crossing | 44.05939, -113.87791 | |
| 5 | Mackay Reservoir — Upper IDFG access site | Access / boat ramp | 43.96791, -113.71068 | Shoreline access at the head of Mackay Reservoir. |
| 6 | Mackay Reservoir — Lower IDFG access site | Access / boat ramp | 43.96346, -113.70271 | |
| 7 | Joseph T. Fallini Campground BLM Challis Field Office | Campsite | 43.96137, -113.67952 | BLM campground on Mackay Reservoir; the agency also lists it as the Mackay Reservoir Recreation Site. |
| 8 | Mackay Dam Irrigation dam | Dam / hazard | 43.95178, -113.67261 | |
| 9 | Big Lost River — Lower IDFG access site | Access / boat ramp | 43.94085, -113.65016 | The tailwater access below Mackay Dam. |
| 10 | City of Mackay Tourist Park City of Mackay | Park / conservation area | 43.91177, -113.62207 | |
| 11 | River Park RV Park Private · Mackay | Campsite | 43.90995, -113.61988 | |
| 12 | Marinac Fishing Access IDFG access site · Smelter Avenue, Mackay | Access / boat ramp | 43.90269, -113.61692 | In-town access at the Smelter Avenue crossing. |
| 13 | White Knob Motel & RV Park Private · below Mackay | Campsite | 43.89392, -113.57737 |
| # | Point | Type | Lat, Lon | Notes |
|---|---|---|---|---|
| 14 | 4080 West Bridge County road crossing | Bridge crossing | 43.87045, -113.51248 | |
| 15 | Stennett IDFG access site | Access / boat ramp | 43.85937, -113.47132 | |
| 16 | Moose Crossing RV Park Private | Campsite | 43.86177, -113.45273 | |
| 17 | Rothwell IDFG access site | Access / boat ramp | 43.84707, -113.44237 | The lowest agency access on the Big Lost; below here the river runs through private farmland. |
| 18 | Moore Diversion Irrigation diversion dam | Dam / hazard | 43.78602, -113.35904 | |
| 19 | 3175 North Bridge County road crossing above Moore | Bridge crossing | 43.73624, -113.35855 | |
| 20 | Moore City Park City of Moore | Park / conservation area | 43.73384, -113.36681 | OSM spells the name with a double space; corrected here. |
| 21 | Aikele Road Bridge County road crossing above Arco | Bridge crossing | 43.63823, -113.32654 | |
| 22 | Bottolfsen Park City of Arco | Park / conservation area | 43.63227, -113.30431 | |
| 23 | Mountain View RV Park Private · Arco | Campsite | 43.62637, -113.30538 | |
| 24 | 2400 North Bridge County road crossing at Arco | Bridge crossing | 43.62395, -113.31211 | |
| 25 | Idaho Medal of Honor Highway Bridge US 20/26 at Arco | Bridge crossing | 43.61545, -113.31005 | The last crossing on this sheet. |
Gauge: USGS 13120500 — BIG LOST RIVER AT HOWELL RANCH NR CHILLY ID. Live flow on the web page.
Species: Brook Trout, Brown Trout, Mountain Whitefish, Rainbow Trout
Regulations: idfg.idaho.gov/rules/fish
Emergency: call 911 and give the number of the nearest point on this map plus its coordinates.
Howell Ranch reach near Chilly - the public water at the gauge itself, reached from the Trail Creek Road.
Wildhorse Creek Road - Forest Service access to the upper headwater forks.
Copper Basin Road - public access to the other main headwater arm above the confluence.
Mackay Reservoir inlet - access where the upper river enters the reservoir.
Highway 93 bridges between Chilly and Mackay - limited roadside access, much of it bordered by private ranch.
Mackay city park and the reach below town - lower-valley bank access.
Bureau of Land Management ground in the Lost River valley - scattered public reaches worth mapping in advance.
Spring: snowmelt from the Pioneers and the Lost River Range keeps the river high and off-colour into June.
Summer: the main season, with terrestrial fishing at its best and irrigation withdrawals cutting flows through August.
Fall: flows recover as the headgates close, and the fishing is at its best in cool weather with almost no pressure.
Winter: cold, low and largely inaccessible, with deep snow