diff --git a/render.c b/render.c
index aba0f41..5f72045 100644
--- a/render.c
+++ b/render.c
@@ -148,6 +148,7 @@ SDL_Surface *render_flak(date now)
 	SDL_FillRect(rv, &(SDL_Rect){.x=0, .y=0, .w=rv->w, .h=rv->h}, ATG_ALPHA_TRANSPARENT&0xff);
 	for(unsigned int i=0;i<nflaks;i++)
 	{
+		if(!flaks[i].mapped) continue;
 		if(!datewithin(now, flaks[i].entry, flaks[i].exit)) continue;
 		bool rad=!datebefore(now, flaks[i].radar);
 		unsigned int x=flaks[i].lon, y=flaks[i].lat, str=flaks[i].strength;
diff --git a/run_raid.c b/run_raid.c
index af9e4e9..47b7d57 100644
--- a/run_raid.c
+++ b/run_raid.c
@@ -486,6 +486,7 @@ screen_id run_raid_screen(atg_canvas *canvas, game *state)
 				state->bombers[k].navlon=0;
 				state->bombers[k].driftlat=0;
 				state->bombers[k].driftlon=0;
+				state->bombers[k].flakreport=-1;
 				double askill=0; // Airmanship
 				for(unsigned int l=0;l<MAX_CREW;l++)
 				{
@@ -1026,6 +1027,9 @@ screen_id run_raid_screen(atg_canvas *canvas, game *state)
 							unsigned int x=flaks[i].lon/2, y=flaks[i].lat/2;
 							double wea=((x<128)&&(y<128))?state->weather.p[x][y]-1000:0;
 							double preccap=160.0/(5.0*(moonillum+.3)/(double)(8+max(4-wea, 0)));
+							// We have been fired at by this flak, so we know it exists
+							if(!flaks[i].mapped)
+								state->bombers[k].flakreport=i;
 							if(rad) preccap=min(preccap, window?960.0:480.0);
 							if(brandp(flaks[i].strength*flakscale/min((12+flaks[i].shots++)*40.0, preccap)))
 							{
@@ -1899,7 +1903,10 @@ screen_id run_raid_screen(atg_canvas *canvas, game *state)
 				i--;
 				continue;
 			}
-			else if(state->bombers[i].damage>50)
+			int fr=state->bombers[i].flakreport;
+			if(fr>=0&&fr<(int)nflaks)
+				flaks[fr].mapped=true;
+			if(state->bombers[i].damage>50)
 			{
 				fa_append(&state->hist, state->now, (harris_time){11, 00}, state->bombers[i].id, false, type, 1);
 				state->bombers[i].failed=true; // mark as u/s
diff --git a/save/save-format b/save/save-format
index a48ac06..7120ff1 100644
--- a/save/save-format
+++ b/save/save-format
@@ -38,6 +38,10 @@ for(i=0;i<nfighters;i++)
 		"Type %u:%u,%u,NOID\n", fighter[i].type, fighter[i].base, fighter[i].radar
 	or
 		"Type %u:%u,%u,%s\n", fighter[i].type, fighter[i].base, fighter[i].radar, pacid(fighter[i].id)
+"Flaks:%u\n", nflaks // should be a constant
+optional // else assume flags=0 for all sites
+	for(i=0;i<nflaks;i++)
+		"Site %u:%u\n", i, flags // flag 1 is flaks[i].mapped; no others defined
 either
 {
 	"Targets:%hhu\n", ntargs // should be a constant
diff --git a/saving.c b/saving.c
index 0220241..81872f2 100644
--- a/saving.c
+++ b/saving.c
@@ -44,6 +44,8 @@ int loadgame(const char *fn, game *state)
 	state->weather.seed=0;
 	for(unsigned int i=0;i<DIFFICULTY_CLASSES;i++) // default everything to medium
 		state->difficulty[i]=1;
+	for(unsigned int i=0;i<nflaks;i++) // all flaksites are unmapped if not saved
+		flaks[i].mapped=false;
 	while(!feof(fs))
 	{
 		char *line=fgetl(fs);
@@ -506,6 +508,51 @@ int loadgame(const char *fn, game *state)
 				}
 			}
 		}
+		else if(strcmp(tag, "Flaks")==0)
+		{
+			unsigned int snflaks;
+			f=sscanf(dat, "%u\n", &snflaks);
+			if(f!=1)
+			{
+				fprintf(stderr, "1 Too few arguments to tag \"%s\"\n", tag);
+				e|=1;
+			}
+			else if(snflaks!=nflaks)
+			{
+				fprintf(stderr, "2 Value mismatch: different nflaks value\n");
+				e|=2;
+			}
+			else
+			{
+				for(unsigned int i=0;i<nflaks;i++)
+				{
+					free(line);
+					line=fgetl(fs);
+					if(!line)
+					{
+						fprintf(stderr, "64 Unexpected EOF in tag \"%s\"\n", tag);
+						e|=64;
+						break;
+					}
+					unsigned int j;
+					unsigned int flags;
+					f=sscanf(line, "Site %u:%u\n", &j, &flags);
+					if(f!=2)
+					{
+						fprintf(stderr, "1 Too few arguments to part %u of tag \"%s\"\n", i, tag);
+						e|=1;
+						break;
+					}
+					if(j!=i)
+					{
+						fprintf(stderr, "4 Index mismatch in part %u (%u?) of tag \"%s\"\n", j, i, tag);
+						e|=4;
+						break;
+					}
+					flaks[i].mapped=flags&1;
+				}
+			}
+		}
 		else if(strcmp(tag, "Targets init")==0)
 		{
 			double dmg,flk,heat,flam;
@@ -807,6 +854,12 @@ int savegame(const char *fn, game state)
 			flags |= 1;
 		fprintf(fs, "Type %u:%u,%u,%s\n", state.fighters[i].type, state.fighters[i].base, flags, p_id);
 	}
+	fprintf(fs, "Flaks:%u\n", nflaks);
+	for(unsigned int i=0;i<nflaks;i++)
+	{
+		unsigned int flags=(flaks[i].mapped?1:0);
+		fprintf(fs, "Site %u:%u\n", i, flags);
+	}
 	fprintf(fs, "Targets:%u\n", ntargs);
 	for(unsigned int i=0;i<ntargs;i++)
 		fprintf(fs, "Targ %u:"FLOAT","FLOAT","FLOAT","FLOAT"\n", i, CAST_FLOAT state.dmg[i], CAST_FLOAT (targs[i].flak?state.flk[i]*100.0/(double)targs[i].flak:0), CAST_FLOAT state.heat[i], CAST_FLOAT state.flam[i]);
diff --git a/types.h b/types.h
index 4809ece..09301fa 100644
--- a/types.h
+++ b/types.h
@@ -242,6 +242,7 @@ typedef struct
 	//STRENGTH:LAT:LONG:ENTRY:RADAR:EXIT
 	unsigned int strength, lat, lon;
 	date entry, radar, exit;
+	bool mapped; /* Have we learned of this flaksite's existence? */
 	/* for Himmelbett fighter control */
 	unsigned int heat; // number of bombers in the vicinity
 	signed int ftr; // index of fighter under this radar's control (-1 for none)
@@ -283,6 +284,7 @@ typedef struct
 	bool fix; // have a navaid fix?  (controls whether to drop skymarker)
 	unsigned int startt; // take-off time
 	unsigned int fuelt; // when t (ticks) exceeds this value, turn for home
+	int flakreport; // first unmapped flaksite we encountered
 }
 ac_bomber;